Lift Coefficient Research Papers - Academia.edu (original) (raw)

2025, Al-Nahrain Journal for Engineering Sciences

This study examines the flow behavior and lift coefficient variations of a NACA 4415 airfoil using different vortex generator configurations. Experimental investigations are conducted in a subsonic wind tunnel at a Reynolds number of 1.8 x 10 5. The airfoil is tested with two types of vortex generators, namely the dome vortex and the convergent-divergent vortex, positioned at 10%, 28%, and 60% chord locations. Experimental lift coefficients are compared with Airfoil Tools database, showing consistent agreement within an angle of attack range of 0 to 18 degrees. At small angles of attack (0 to 8 degrees), the lift coefficients of the NACA 4415 airfoil with the dome vortex at 10%, 28%, and 60% chord positions are lower compared to the baseline configuration. However, beyond 14 degrees, the highest lift coefficient value after the angle range of 14-18 degrees is achieved at the 60% chord position with the dome vortex, 10.43% increase compared to the baseline lift coefficient. Furthermore, the best value for the lift coefficient after the angle range of 16-18 degrees at the 10% chord position is achieved with the dome vortex, where the maximum lift coefficient 9.4% increase compared to the baseline lift coefficient. It is noted that the baseline configuration consistently outperforms the convergent-divergent vortex configurations.

2025, AIAA Journal

In this numerical-theoretical study, a linear BiGlobal stability analysis of the steady massively separated flow around a NACA 4415 airfoil was performed at a low Reynolds number (Re 200) and a high angle of attack (α 18 deg) close to a wavy ground, with a focus on the effect of three different types of stationary roughness: 1) a perfectly flat ground, 2) a wavy ground with small-amplitude undulations, and 3) a wavy ground with large-amplitude undulations. On increasing the undulation amplitude h 0 of the ground but keeping the mean ground clearance constant, it was found that the lift coefficient increased owing to an increase in the static pressure under the airfoil, which is reminiscent of the conventional ground effect over a flat surface. However, it was also found that the leading flow perturbation was the three-dimensional stationary global mode and not the two-dimensional traveling Kelvin-Helmholtz mode, contrary to the results of previous analogous studies of linear global instability of massively separated flow away from the ground. This study provides new insight into the stability of airfoil-ground flow systems at a low Reynolds number and a high angle of attack, contributing to a better understanding of the ground-effect aerodynamics of small insects and micro air vehicles flying over rough waters or complex terrain.

2025, International Journal of Sustainable Aviation (IJSA)

The nose cones of aerospace vehicles act as the point of first contact with the oncoming flow of air. Consequently, evaluating and enhancing their properties becomes crucial for the overall performance of the vehicle. In this paper, the aerodynamic performance of slotted tangent ogive nose cones with a cylindrical afterbody has been assessed numerically for the Mach number of 0.1. The number of slots and the slot depth has been varied in order to investigate its effects on the lift and resulting side forces. The case of two symmetric slots on the nose cone, each of 0.001 m depth exhibited an enhancement in the lift-to-drag ratio at an angle of attack of 15°. The results also demonstrated the effectiveness of slots in controlling the generation of wake vortices. The case with four slots of 0.001 m depth each, vertically restricted the leeward vortices below the tip of the cylindrical forebody.

2025, 29th AIAA Applied Aerodynamics Conference

2025, Malaysian Journal of Fundamental and Applied Sciences

Research on spoiler available to date was mainly done to optimize the performance of spoiler in non-zero yaw condition. However, the effect of spoiler is most needed during cornering to ensure the stability of the vehicle. Therefore, this study aims to inspect the effect of yaw angles change on the aerodynamic performance of the NACA 0018 wing spoiler and the subsequent influence on the flow characteristics of the hatchback vehicle. Computational Fluid Dynamics (CFD) has been applied to model the flow. Comparison between numerically obtained results and experimental data was done to validate the CFD method. The findings show that both the drag coefficient, Cd, and lift coefficient, Cl have increased with increasing yaw angle. However, the spoiler has performed in favor of reducing the Cd and Cl even with increasing yaw angle. The averaged proportion contributions from the spoiler to the overall Cd and Cl are 2.7% and 4.1%, respectively. The other body parts that have contributed to ...

2025

This paper discusses the impact of the external store on the aerodynamic performance of the light aircraft model in the subsonic region. Light aircrafts are normally used to train pilots, survey, leisure and transportation. To date, there have been a lot of small aircrafts were used for a strategic purposes where an external store either external fuel storage or armament has been installed on its wing. Examples of such aircraft are KAI-KA1, A29 Super Tucano and Beechcraft AT-6. Therefore it is important to study the effect of this external store installation on the aerodynamic characteristics of a small aircraft. An available light aircraft model of UTM Low speed wind tunnel (UTM-LST) has been modified so that a generic external store can be mounted on the lower surface of the wing. Two set of experiments were carried out on the model which were; the experimental with the external store and followed by the experimental without external store as a benchmark of tested configuration. T...

2025, International Journal of Modern Physics B

Recently, the Gurney Flap (GF) has been used to improve the performance of Horizontal Axis Wind Turbine (HAWT) by enhancing its lift coefficient. Compared to HAWT, research on GF application for Vertical Axis Wind Turbine (VAWT) is very limited. Moreover, most works studied a GF geometry attached to the trailing edge of a stationary airfoil, without considering the rotating effect experienced by VAWT. For this reason, a three-straight-bladed VAWT rotating blade with GF is studied by transient RANS simulation together with a stress-blended eddy simulation (SBES) turbulence model to investigate the GF height effect and the flow characteristics near the blade trailing edge. Results have shown that by introducing the blade rotating, an optimum GF height is found to be 3% of the blade chord, slightly higher than 2% chord in a stationary airfoil case. In addition, the presence of GF can delay deep stall of VAWT blades, thus eliminating negative instantaneous moment coefficient and improvi...

2025

In this paper the design and development of a free flow vertical axis wind turbine was carried out. The turbines are usually of two categories 1. Horizontal Axis Wind Turbine (HAWT) 2. Vertical Axis Wind Turbines (VAWT) , of these the VAWT has very complicated aerodynamics, hence more emphasis is on development of VAWT as it requires very less space and generates power at a much lower wind speed than the conventional one. The VAWT was developed with the help of Fiber Reinforced Polymer (FRP), Mild Steel and Nylon bushes. The blade profile was selected from the symmetrical profile of NACA. Once the turbine was developed it was tested for its performance at various locations and the results shows that the turbine can generate power at a low wind speed of 5 m/s, which will suit for Indian conditions.

2025, Journal of Marine Science and Engineering

In this study we investigated the performance of NACA 0012 hydrofoils aligned in tandem using parametric method and Neural Networks. We use the 2D viscous numerical model (STAR-CCM+) to simulate the hydrofoil system. To validate the numerical model, we modeled a single NACA 0012 configuration and compared it to experimental results. Results are found in concordance with the published experimental results. Then two NACA 0012 hydrofoils in tandem configuration were studied in relation to 788 combinations of the following parameters: spacing between two hydrofoils, angle of attack (AOA) of upstream hydrofoil and AOA of downstream hydrofoil. The effects exerted by these three parameters on the hydrodynamic coefficients Lift coefficient (C L ), Drag Coefficient (C D ) and Lift-Drag Ratio (LDR), are consistent with the behavior of the system. To establish a control system for the hydrofoil craft, a timely analysis of the hydrodynamic system is needed due to the computational resource constraints, analysis of a large combination and time consuming of the three parameters established. To provide a broader and faster way to predict the hydrodynamic performance of two hydrofoils in tandem configuration, an optimal artificial neural network (ANN) was trained using the large combination of three parameters generated from the numerical simulations. Regression analysis of the output of ANN was performed, and the results are consistent with numerical simulation with a correlation coefficient greater than 99.99%. The optimized spacing of 6.6c are suggested where the system has the lowest C D while obtaining the highest C L and LDR. The formula of the ANN was then presented, providing a reliable predicting method of hydrofoils in tandem configuration.

2025, Journal of Marine Science and Engineering

2025, Space Plane and Hypersonic Systems and Technology Conference

An investigation of lift, drag, and pitching moment characteristics of a wing-body combination with trailing edge flaps has been conducted to study the effect of nose bluntness and flap deflection. The seventy degree swept back delta wing had sharp leading and trailing edges and was fitted along the centre line of a blunted conecylinder body. The characteristics for the cone-cylinder alone were also obtained to evaluate the effect of nose bluntness on the aerodynamic performance of the conecylinder body. The tests were conducted in the College of Aeronautics gun tunnel at M,= 8.2 and Re,= 93500km. The model

2025, Journal of the Brazilian Society of Mechanical Sciences and Engineering

In the present study, the effect of hinge position (H) has been numerically investigated to find the appropriate position for improving the aerodynamic performance of the NACA 0012 flapped airfoil. In addition, perpendicular and tangential suctions have been applied to control the flow separation and enhance the aerodynamic performance over the NACA 0012 flapped airfoil at each different hinge positions. The simulations were carried out at a Reynolds number of 5 × 10 5 (Ma = 0.021) based on two-dimensional incompressible unsteady Reynolds-averaged Navier-Stokes calculations to determine the adequate hinge position. The turbulence was modeled using the shear stress transport k-ω turbulence model. The effect of perpendicular suction (θ jet = -90°) and tangential suction (θ jet = -30°) was computationally studied over NACA 0012 flapped airfoil for five different hinge positions (H = 0.7c, 0.75c, 0.8c, 0.85c and 0.9c) and a flap deflection (δ f ) of 15°. Based on the results, the hinge position significantly affects the aerodynamic performance of the airfoil. The lift coefficient increased clearly as the hinge position moved to the trailing edge of the airfoil. Using perpendicular suction caused to increase the lift coefficient and decrease the drag coefficient. Consequently, the maximum value of the lift-to-drag ratio (C L /C D ) for perpendicular and tangential suctions was achieved about 35.8% and 25.1% higher than that of the case without suction at an angle of attack of 12° and H = 0.9c. Also, the effect of perpendicular suction was more considerable compared to the tangential suction. This caused a reduction in the size of the recirculation zone from 0.5 to 0.09 of the airfoil chord length and also transferred it from 1.13 to 1.18 of the airfoil chord length.

2025, International Journal of Energy Studies

Performance measurement of NACA 2414 and NACA 6409 series airfoils in the range of 1x10 6 constant Reynolds number and 0-20 0 attack angles. Comparison of different features such as lift (Cl) and drag (Cd) coefficients, pressure distribution on the wings, power coefficients with Q-Blade software.  Analyzes were made using a calculation method based on Blade Element Momentum (BEM) theory. Comparative analysis of moment, torque, thrust and power coefficient based on tip speed ratios for both airfoils.

2025

This paper presents the results of an experimental investigation of two rotary-wing UAV designs. The primary goal of the investigation was to provide a set of interactional aerodynamic data for an emerging class of rotorcraft. The present paper provides an overview of the test and an introduction to the test articles, and instrumentation. Sample data in the form of a parametric study of fixed system lift and drag coefficient response to changes in configuration and flight condition for both rotor off and on conditions are presented. The presence of the rotor is seen to greatly affect both the character and magnitude of the response. The affect of scaled stores on body drag is observed to be dependent on body shape.

2025

A conceptual design optimization methodology was developed for a medium range box wing aircraft. A baseline conventional cantilever wing aircraft designed for the same mission and payload was also optimized alongside a baseline box wing aircraft. An empirical formula for the mass estimation of the fore and aft wings of the box wing aircraft was derived by relating conventional cantilever wings to box wing aircraft wings. The results indicate that the fore and aft wings would use the same correction coefficient and that the aft wing would be lighter than the fore wing on the medium range box wing aircraft because of reduced sweep. As part of the methodology, a computational study was performed to analyze different wing/tip fin fixities using a statically loaded idealized box wing configuration. The analyses determined the best joint fixity by comparing the stress distributions in finite element torsion box models in addition to aerodynamic requirements. The analyses indicates that th...

2025, 39th Aerospace Sciences Meeting and Exhibit

The aerodynamic characteristics of a Circulation Control Wing (CCW) airfoil have been numerically investigated, and comparisons with experimental data have been made. The configuration chosen was a supercritical airfoil with a 30 degree dual-radius CCW flap. Steady and pulsed jet calculations were performed. It was found that the use of steady jets, even at very small mass flow rates, yielded a lift coefficient that is comparable or superior to conventional high-lift systems. The attached flow over the flap also gave rise to lower drag coefficients, and high L/D ratios. Pulsed jets with a 50% duty cycle were also studied. It was found that they were effective in generating lift at lower reduced mass flow rates compared to a steady jet, provided the pulse frequency was sufficiently high. This benefit was attributable to the fact that the momentum coefficient of the pulsed jet, during the portions of the cycle when the jet was on, was typically twice as much as that of a steady jet. ∞ ρ = Free Stream Density jet ρ = Jet Blowing Density * Graduate Research Assistant, Student Member AIAA. ** Regents Professor, Associate Fellow AIAA.

2025, Journal of Engineering

The aerodynamic efficiency of wind turbines is greatly influenced by the shape of their airfoils. In this study, four airfoils were optimized to enhance the performance of a small horizontal axis wind turbine. The optimization process involved adjusting the thickness and camber of the airfoils using the blade element momentum method and particle swarm optimization technique. The goal was to find the most aerodynamically efficient airfoil based on the thickness-to-camber ratio. The optimized airfoils were compared to select the best one for a three-blade, 6-m diameter turbine configuration. The results showed that the optimized microturbine achieved better efficiency than the baseline turbines and those optimized by other researchers. Notably, the study also rigorously validated the blade element momentum-particle swarm optimization methodology through experimental methods, providing robust support for our findings.

2025, Journal of Fluids and Structures

• URANS results were validated with the experimental data. • Longitudinal vortex structure was visualized and provided the supplementary movies. • Limiting streamlines showed the flow patterns around the cylinder surface. • Aerodynamic... more

2025, Journal of Fluids and Structures

2025, The International Conference on Applied Mechanics and Mechanical Engineering (Print)

This work aims to study and simulate the behavior of flow over SAFAT-01's wing using numerical simulation based on solving Reynolds's Averaged Navier-Stokes equations coupled with K-ω turbulent model. The wing model is simple rectangular with elliptical ends. In the present work, aerodynamics characteristics and different flow phenomena were predicted at different design conditions (e.g. at different angles of attack) and at Re=5.2×10 6 . The present study analysis the vortices which occur over wing and captured their effective regions at critical design conditions. This study indicates that the maximum lift coefficient for SAFAT-01's wing is 1.44 occurred at stall angle of attack 12 o , maximum lift to drag ratio (L/D) is 26 which occurs at -4 o , and the zero lift drag coefficient is 0.0142. To validate this numerical simulation, a typical wing which found in Ref. was analyzed, a comparison between predicted results and available results indicate that this numerical simulation has high ability for predicting the aerodynamics characteristics.

2025, Experimental Thermal and Fluid Science

The flow characteristics over a symmetrical airfoil--NACA 0015--are studied experimentally in a low speed wind tunnel. The pressure distribution on the airfoil surface was obtained, lift and drag forces were measured and mean velocity profiles were obtained over the surface. The wake region was also explored in detail and measurements of mean velocity and turbulence intensities were performed at two stations downstream of the trailing edge. Experiments were carried out by varying the angle of attack, a, from 0°to 10°and ground clearance of the trailing edge from the minimum possible value to one chord length. It was found that high values of pressure coefficient are obtained on the lower surface when the airfoil is close to the ground. This region of high pressure extended almost over the entire lower surface for higher angles of attack. As a result, higher values of lift coefficient are obtained when the airfoil is close to the ground. The flow accelerates over the airfoil due to flow diversion from the lower side, and a higher mean velocity is observed near the suction peak location. The pressure distribution on the upper surface did not change significantly with ground clearance for higher angles of attack. The upper surface suction causes an adverse pressure gradient especially for higher angles of attack, resulting in rapid decay of kinetic energy over the upper surface, leading to a thicker wake and higher turbulence level and hence a higher drag. The lift was found to drop at lower angles of attack at some values of ground clearance due to suction effect on the lower surface as the result of formation of a convergent-divergent passage between the airfoil and the ground plate. For the angle of attack of 12.5°, a very thick wake region was observed and higher values of turbulence intensity were recorded.

2025, Mechanical Engineering Advances

This study focuses on optimizing the SG6043 airfoil for small wind turbines (SWTs) operating at low Reynolds numbers (Re = 100,000 to 600,000). Using XFOIL software, 71 airfoils were analyzed, and the SG6043 airfoil demonstrated the highest lift-to-drag ratio (CL/CD). Three modified airfoils were designed by varying the thickness-to-camber ratio (t/c) between 0.5 and 1.5. The SG6043 modified 1 airfoil achieved a maximum CL/CD of 184.85 at Re = 600,000, outperforming other airfoils. These findings provide valuable insights for designing more efficient SWTs for low wind speed applications. At first, 71 airfoils, including some symmetrical National Advisory Committee for Aeronautics (NACA) 4-digit, NACA 5digit, Eppler series, Selig series, and other airfoils with higher aerodynamic performance at Reynolds numbers (Re) of 100,000 to 600,000 (the operation range for small wind turbines, SWTs), were chosen and analyzed in XFOIL software to determine their lift-to-drag ratio (CL/CD). The results showed that the SG6043 airfoil had the highest maximum CL/CD when compared to the other airfoils. To investigate and enhance the shape modification of the airfoil utilizing variations in thickness-to-camber ratio (t/c) and to determine the ideal t/c at Re of 100,000 to 600,000, the SG6043 airfoil was used. Based on the findings, 0.5 to 1.5 was the optimum t/c at Re of 100,000 to 600,000 for the development of the SG6043 airfoil, which had the maximum CL/CD. Then, three airfoils with varying thicknesses and cambers were designed and analyzed at the mentioned Re, with the optimal t/c being between 0.5 and 1.5. The findings indicated that when the Re increased, the SG6043 modified airfoil's aerodynamic efficiency enhanced. SG6043 modified 1 airfoil presented the greatest CL/CD of 184.85 at a Re of 600,000. For the SG6043 modified 2 airfoil, the maximum stall angle (AoAstall) of 13° was demonstrated for Re of 300,000 to 600,000. Maximum CL/CD values for SG6043 modified 1, SG6043 modified 3, and SG6043 modified 2 were 184.85, 182.36, and 177.25, respectively. SG6043 modified 2, SG6043 modified 1, and SG6043 modified 3 had peak lift coefficients (CL) of 1.798, 1.79, and 1.788, respectively. SG6043 modified airfoils performed well in the drag bucket when initial lift increases were accompanied by either steady or decreasing drag.

2025

This study investigated the performance of blown airfoil. Two types of blown airfoil were developed. The integrated parts of the airfoils were investigated in the subsonic wind tunnel to study the aerodynamic forces. Each airfoil was implemented with a blower at different locations on the upper surface and was tested in the wind tunnel, with different Reynolds numbers, and with and without blower. The results showed that the airfoil with air blower produced a very significant additional 35% lift force compared to airfoil without air blower. The experimental result also exhibited 7% higher lift coefficient for air blower compared to numerical analysis.

2025, Journal of Fluid Mechanics

We employ three-dimensional direct and large-eddy numerical simulations of the vibrations and flow past cylinders fitted with free-to-rotate U-shaped fairings placed in a cross-flow at Reynolds number 100 Re 10, 000. Such fairings are nearly-neutrally buoyant devices fitted along the axis of long circular risers to suppress vortex-induced vibrations (VIV). We consider three different geometric configurations, a homogeneous fairing, and two configurations (denoted A and AB) involving a gap between adjacent segments. For the latter two cases, we investigate the effect of the gap on the hydrodynamic force coefficients and the translational and rotational motions of the system. For all configurations, as the Reynolds number increases beyond 500, both the lift and drag coefficients decrease. Compared to a plain cylinder, a homogeneous fairing system (no gaps) can help reduce the drag force coefficient by 15% for reduced velocity U * = 4.65, while a type A gap system can reduce the drag force coefficient by almost 50% for reduced velocity U * = 3.5, 4.65, 6, and, correspondingly, the vibration response of the combined system, as well as the fairing rotation amplitude are substantially reduced. For a homogeneous fairing, the cross-flow amplitude is reduced by about 80%, whereas for fairings with a gap longer than half a cylinder diameter, VIV are completely eliminated, resulting in additional reduction in the drag coefficient. We have related such VIV suppression or elimination to the features of the wake flow structure. We find that a gap causes the generation of strong streamwise vorticity in the gap region that interferes destructively with the vorticity generated by the fairings, hence disorganizing the formation of coherent spanwise cortical patterns. We provide visualization of the incoherent wake flow that leads to total elimination of the vibration and rotation of the fairing-cylinder system. Finally, we investigate the effect of the frictional coefficient between cylinder and fairing; the effect overall is small, even when the frictional coefficients of adjacent segments are different. In some cases the equilibrium positions of the fairings are rotated by a small angle on either side of the centerline, in a symmetry-breaking bifurcation, which depends strongly on Reynolds number.

2025, Imprensa da Universidade de Coimbra eBooks

This paper presents an investigation into the impact of wind speed on the interaction of wind driven surface fire with an idealized building structure. The open-source large eddy simulation (LES) fire dynamic solver, FireFOAM, was used to simulate fires burning with an intensity of 10 MW/m under different wind speeds. The numerical data was validated using a wind only simulation which compared aerodynamic data to the previous full size experimental and numerical studies. The results show the aerodynamic flow characteristics and their interaction with the idealized structure located downstream of the fire source. Increase in wind speed showed a linear relationship to increase in the coefficient of lift on the building. The local coefficient of pressure on the building was calculated which indicated significant risk of damage due to aerodynamic lift caused by buoyant fire updraft. The results also show that at a constant fire intensity, increasing wind speed leads to an increase in the average temperature of the domain downstream of the fire to a certain value and then decreases.

2025, TECCIENCIA

The present research study presents the results of the aerodynamic analysis of a USB AERO aircraft using computational fluid dynamics (CFD) in operational conditions of cruise flight at an angle of attack of 3.5 degrees. The ANSYS FLUENT computational tool was used, with which the lift, drag and longitudinal momentum coefficients were determined. Additionally, the aircraft was analyzed at different angles of attack in order to determine aerodynamic characteristics such as the highest lift coefficient and the loss angle, in addition to establishing the maximum aerodynamic efficiency.

2025, Volume 1: 20th Biennial Conference on Mechanical Vibration and Noise, Parts A, B, and C

A reduced-order model for the two-dimensional flow over a stationary circular cylinder is examined. The lift is modeled with the van der Pol equation with three parameters; it models self-excited self-limiting systems. The drag is modeled as the sum of a mean term and a time-varying term proportional to the product of the lift and its time derivative. The transient and steady-state flows are calculated using a CFD code based on the unsteady Reynolds-averaged Navier-Stokes equations. The steady-state lift and drag CFD results are used to identify the three parameters in the lift model using a combination of higher-order spectral techniques and perturbation methods. The model is validated using steady-state numerical simulations for three cases describing low, moderate, and high Reynolds number flows. Then, the model is shown to reproduce the transient lift and drag calculated with the CFD code.

2025, International Journal of Aerospace Innovations

Reynolds Averaged Navier-Stokes (RANS) simulations and analysis of a trapezoidal three element high lift wing, using CFD++, is presented in this paper. Parametric study of grid and solver effect has been done. Requirements of the grid refinement at critical locations of the geometry are discussed. Optimized volume stretching ratio has been identified through the grid independent study. Simulations using various turbulence models available in CFD++ with various grids have been performed and results are documented. Predicted trends of lift coefficient (C L ) and its maximum value (C Lmax ) are in close agreement with experimental data.

2025

In this paper, a idea of having a streamlined hollow shape is introduced to the basic NACA airfoil namely, NACA 0018, which is symmetrical along the chord. To obtain detailed information about the pressure, lift, drag, and velocity distribution over the airfoil, along with the coefficient of lift and drag forces, I used popular advanced software such as Catia for design and modelling, structural sizing was also done in Catia, aerodynamic meshing was done in ANSYS fluent, it also helped me to obtain flow solutions. The optimization of the wing is to reduce the weight of the wing along with some decrease in the negative lift for the negative angle of attack of the wing with approximately small decrement in drag for positive angle of attack. Therefore, according to the Breguet equation, there will be the increase in range. According to the power and effective coding of the ANSYS and CATIA, I obtained increase in range in the domain of negative angle of attack. The second most effective...

2025

A quick reference guide on the Buckingham Pi method, used to recast problems in terms of dimensionless parameters and for dimensional reduction. Included are commonly used dimensionless ratios and other concepts related to scaling.

2025, Deleted Journal

In this paper, airfoils' computational fluid dynamics study assessed aerodynamic characteristics and vortex development by varying the angle of attack (α) and flap deflection angles. The flow characteristics over three airfoil models (NACA0021, NACA2409, NACA2409+Fowler flap) were numerically simulated. The approach of the finite volume model was employed to solve the mass and momentum governing equation. The reliable Spalart-Allmaras (S-A) turbulent model was used and validated using reported data from the experiment in terms of lift and drag coefficients. The numerical simulation successfully obtained good results in analyzing fluid flow over the airfoil. Detailed explanations of simulation steps were also presented. The vortex development and air separation were clearly captured. The results of the symmetric airfoil showed that the vortex shedding regimes occurred at α = 8 o, and the critical stall angle was about 14 o . The value was higher for the NACA2409, where the airflow exhibited a relatively more stable behavior. Moreover, it is evident that flap addition altered lift-drag characteristics. The value of the lift-to-drag ratio increased due to the increase of . The parametric study was done on the α and flap deflection angle to attain the desirable airfoil configuration. The maximum result of airfoil configuration was obtained on the NACA2409 at α = 12 o with 10 0 flap deflection angles while it enhanced the lift coefficient by about 54%. This study is beneficial for initial aircraft design on the aerodynamics aspect of an airfoil and a wing analysis.

2025, Journal of Fluids and Structures

Tile reliablity and applicability of various coating defect detecting techniques are investigated utilizing mock pipe. It is shown that both close interval potential survey and dc voltage gradient methods are impertinent as field techniques : They require considerable cathodic polarization in order to effectively locate the coating defects. DC voltage gradient with current interruption technique is recommended as a viable field method in that it is able to precisely locate the defects irrespective of CP condition. Utilizing this method field survey was undertaken for the KGC's pipeline of 120 km and 106 assumed defects were located.

2025, European Journal of Emergency Medicine

2025, IOP Conference Series: Materials Science and Engineering

Blended wing-body (BWB) aircraft having planform configuration similar to those previously researched and published by other researchers does not guarantee that an efficient aerodynamics in term of lift-to-drag ratio can be achieved. In this wind tunnel experimental study, BWB half model is used. The model is also being scaled down to 71.5% from the actual size. Based on the results, the maximum lift coefficient is found to be 0.763 when the angle is at 27.5° after which the model starts to stall. The minimum drag coefficient is 0.014, measured at zero angle of attack. The corrected lift-to-drag ratio (L/D) is 15.9 at angle 7.8°. The scaled model has a big flat surface that surely gives an inaccurate data but the data obtained shall give some insights for future perspective towards the BWB model being tested.

2025, IAES International Journal of Artificial Intelligence

Developing an engineering design is resource-intensive and timeconsuming, particularly for the floats of a floatplane design, due to its complexity and limited testing facilities. Intelligent-based computational design (IBCD) techniques, which integrate computational design techniques and machine learning (ML) algorithms, offer a solution to reduce required testing by providing predictions. This paper proposes a deep learning (DL)based IBCD method for modeling floats' lift-to-drag coefficient ratio (CL/CD), where DL is one of the most powerful ML. The proposed method consists of two phases: hyper-parameter optimization and DL model training and evaluation. A genetic algorithm (GA) is employed in the first phase to explore complex hyper-parameter combinations efficiently. Evaluation of the predicted CL/CD of the floats using the DL model resulted in a satisfactory R-squared of 0.9329 and the lowest mean squared error (MSE) of 0,001536. These results demonstrate the ability of DL model to predict the float's performance accurately and can facilitate further design optimization. Thus, the proposed method can offer a time-efficient and costeffective solution for predicting float performance, aiding in optimizing floatplane designs and enhancing their functionalities.

2025, Çukurova Üniversitesi Mühendislik Fakültesi Dergisi

The effects of a perforated cylinder on the passive flow control around a circular cylinder mounted on a wall were investigated. The perforated cylinder was placed outside of the single circular cylinder concentrically. The large-eddy simulation was used to resolve the flow field. The study was aimed at both reducing the drag coefficient of the single cylinder and controlling the fluctuating forces acting on the single cylinder caused by vortex shedding in the downstream wake. The results showed that the structure of the downstream wake flow of the single cylinder changed significantly after placing the perforated cylinder. For example, von Karman vortices disappeared, and the maximum magnitude of turbulent kinetic energy, TKE, in the downstream wake was reduced. The time-averaged drag coefficient of the single cylinder was decreased by 69%. In addition, the maximum value of the lift coefficient of the single cylinder was reduced by eight times when the perforated cylinder was place...

2025, Çukurova Üniversitesi Mühendislik Fakültesi Dergisi

2025, International Research Journal of Modernization in Engineering Technology and Science

Any airplane needs airfoils because they must reduce drag and produce enough lift to keep the aircraft in the air. Up until now, it has been challenging to develop an airfoil with the necessary aerodynamic qualities. Through experimental investigation, our work compares the aerodynamic characteristics of NACA 4412 and NAC 0015. Our study aims to investigate the optimal experimental performances of NACA 4412 and NACA 0015, as well as identify the most efficient airfoils among the models listed above. Our experiment employing two wooden airfoil models and Reynolds number is now complete.24 x 10.3 x 10^5 and.36×10^5, and used a wind tunnel to calculate the value. Using the values of the lift and drag forces, we were able to determine the lift and drag coefficients. Lastly, it can be observed that NACA 4412 outperforms NACA 0015 in terms of lift coefficient. Furthermore, NACA 4412 will perform better because of its high lift coefficient. Furthermore, it was discovered that NACA 4412 has a lower drag coefficient than NACA 0015. Forces have been used to find the lift coefficient to drag coefficient ratio. We also tried tapping one of our airfoil models, but the short distance makes it difficult to produce a graph

2025, AIAA Journal

The purpose of this work is to analyze a complex high lift configuration for which significant regions of separated flow are present. Current state of the art methods have some difficulty to predict the origin and the progression of this separated flow when increasing the angle of attack. The mechanisms responsible for the maximum lift limit on multielement wing configurations are not clear; this stability analysis could help to understand the physics behind the phenomenon and to find a relation between the flow separation and the instability onset. The methodology presented herein consists in the computation of a steady baseflow solution based on a finite volume discretization and a proposal of the solution for a generalized eigenvalue problem corresponding to the perturbed and linearized problem. The eigenvalue problem has been solved with the Arnoldi iterative method, one of the Krylov subspace projection methods. The described methodology was applied to the NACA0012 test case in subsonic and in transonic conditions and, finally, for the first time to the authors knowledge, on an industrial multi-component geometry, such as the A310 airfoil, in order to identify low frequency instabilities related to the separation. One important conclusion is that for all the analyzed geometries, one unstable mode related to flow separation appears for an angle of attack greater than the one correspondent to the maximum lift coefficient condition. Finally, an adjoint study was carried out in order to *Research Engineer, Airbus Operations S.L.,

2025, Mecánica Computacional

2025

Though it is easier to model and create an airfoil profile in CAD environment using camber cloud of points, after the creation of vane profile it is very difficult to change the shape of profile for analysis or optimization purpose by using cloud of points. In this paper, we investigate and described the creation of airfoil profile in CAD (CATIA) environment using the control point of the camber profile. By means of changing the values of control points, the shape of the profile can be easily changed and also the design of the cambered airfoil was established without affecting the basic airfoil geometry. In this paper, the Quintic Reverse Engineering of Bezier curve formula was used to find the camber control points from the existing camber cloud of points.

2025, ANALISA AERODINAMIKA PADA BODY MOBIL LISTRIK “PIERRE MARIE” TERHADAP KECEPATAN MENGGUNAKAN METODE COMPUTATIONAL FLUID DYNAMICS (CFD)

AERODYNAMIC ANALYSIS OF THE BODY OF THE ELECTRIC CAR "PIERRE MARIE" AGAINST SPEED USING THE COMPUTATIONAL FLUID DYNAMICS (CFD) METHOD. Aerodynamics is a branch of fluid mechanics that studies the movement of air as it interacts with moving objects. This science is very important in the development of vehicle design. Optimal aerodynamic design on a car will reduce the power required to fight air resistance, so that the car can move faster and farther with efficient fuel consumption. The method used is a simulation method using Computational Fluid Dynamics (CFD) to obtain the drag and lift coefficient value using computational techniques, the research conducted focuses on the effect of car speed on the drag and lift coefficient values of the car. The results of the analysis show that the drag and lift coefficient values are directly proportional to the speed, the coefficient values at speeds of 60KM/h, 100 Km/h, and 120 KM/h are 0.0328118, 0.0916523, 0.131823, respectively. And the lift coefficient values are 0.01823, 0.043414, 0.061528, respectively. This car body design is considered aerodynamic because at a speed of 100 km/h the Drag coefficient value still shows a value below 0.1, where in conventional cars the drag value ranges from 0.25-0.30.

2025, Complex & Intelligent Systems

Computational fluid dynamics (CFD) simulations are nowadays been intensively used in aeronautical industries to analyse the aerodynamic performance of different aircraft configurations within a design process. These simulations allow to reduce time and cost compared to wind tunnel experiments or flight tests. However, for complex configurations, CFD simulations may still take several hours using high-performance computers to deliver results. For this reason, surrogate models are currently starting to be considered as a substitute of the CFD tool with a reasonable prediction. This paper presents a review on surrogate regression models for aerodynamic coefficient prediction, in particular for the prediction of lift and drag coefficients. To compare the behaviour of the regression models, three different aeronautical configurations have been used, a NACA0012 airfoil, a RAE2822 airfoil and 3D DPW wing. These databases are also freely provided to the scientific community to allow other r...

2025, Procedia Engineering

In this research work, an experimental investigation of wind effect on pentagonal and hexagonal staggered cylinders was carried out. The study was performed on both the single cylinder and the group consisting of three cylinders, arranged in staggered form, one pentagonal cylinder in the upstream and another two hexagonal cylinder in the downstream side. The test was conducted in an open circuit wind tunnel at a Reynolds number of 4.22 x 10 4 based on the face width of the cylinder across the flow direction in a uniform flow velocity of 13.5 m/s. At first experiment, the test was carried out on a single hexagonal cylinder at various angles of attack from 0° to 50° at a step of 10°. The surface static pressures at the different locations of the cylinder were measured with the help of inclined multi-manometers. Then the test was carried out on a single pentagonal cylinder at various angles of attack from 0° to 72° at a step of 9°. After that the group of three cylinders was taken into consideration for the study and the surface static pressures were measured for various transverse spacing of 2D, 3D, 5D and longitudinal spacing of 1D, 2D, 4D, 6D, 8D, where D is the width of the cylinder across the flow direction. In each case, the wind velocity was kept constant at 13.5 m/s. The pressure coefficients were calculated from the measured values of the surface static pressure distribution on the cylinder. Later the drag and lift coefficients were obtained from the pressure coefficients by the numerical integration method. The results will enable the engineers and architects to design buildings more efficiently. Since the results were expressed in the non-dimensional form they might be applied for the prototype building. Sincere thanks are offered to the staffs of the machine shop and special thanks to Mr. Md. Abul Kalam Azad, instructor of Fluid Mechanics Laboratory of Mechanical Engineering Department of BUET, Dhaka for their kind cooperation in constructing, fabricating and assembling different parts and components of the experimental set-up. iii

2025, Teknika STTKD: Jurnal Teknik, Elektronik, Engine

Kemudian untuk perbandingan nilai ratio lift to drag maximum, diperoleh yaitu Pada geometri airfoil reference (SD 7037) memiliki nilai (CL⁄CD)(max )= 9,96 sedangkan pada geometri airfoil reference (IISHI) memiliki nilai (CL⁄CD )(max )= 8,81. Pada geometri Folded Flat Plate airfoil (SD 7037) memiliki nilai (CL⁄CD)(max ) = 7,61 sedangkan pada geometri Folded Flat Plate airfoil (IISHI) memiliki nilai (CL⁄CD )(max )= 7,37. Kemudian untuk visualisasi aliran fluida dapat diperoleh yaitu hasil visualisasi aliran fluida pada beberapa bagian sudut pandang/ plane dari geometri sayap saat AoA tinggi yaitu plane root sampai plane half wing, Pertama bahwa secara umum pada geometri IISHI (airfoil reference) lebih mudah terjadi aliran turbulensi lebih awal, sedangkan pada geometri SD 7037 (airfoil reference) tidak mudah terjadi aliran turbulensi lebih awal. Kedua bahwa secara umum pola aliran fluida yang terlihat pada geometri FFP airfoil (FFP IISHI) memiliki pola aliran turbulensi yang paling dominan (sangat banyak/besar) sedangkan pada geometri FFP airfoil (FFP SD 7037) memiliki pola aliran turbulensi yang sangat sedikit/kecil..

2025, Aerospace Science and Technology

In this paper, characteristics of separated bubbles and unsteady features of flow fields around a glaze-iced airfoil are investigated. The research was performed using both experimental and numerical approaches. The airfoil was a natural laminar airfoil (NLF-0414) and the ice is considered as the glaze accretion. The experimental measurements were carried out using hot-wire anemometry at Reynolds number of 0.5 × 10 6 and angle of attack ranging from 0 • to 6 • . In numerical calculations, N-S equations were adopted as governing equations and finite-volume technique was employed to solve the equations. Numerical calculations were performed at Reynolds numbers of 0.5 × 10 6 and 1.8 × 10 6 . CFD results and experimental data indicated increasing in the bubble length with increasing in airfoil angle-of-attack. The results showed two separated bubbles in different sizes and also unsteadiness behavior of the flow field which led to low frequency oscillation in lift coefficient with the order of 10 Hz. The frequency of the vortex structures observed in the shear layer measured with hot-wire and it is found that the frequency was in the range of 100 Hz. This frequency was reduced with increasing the angle-of-attack. Vortex shedding was also observed at the downstream of the reattachment location.

2024

The functional box plot is generalized to provide a holistic view of the four dimensional space-time field data resulting from unsteady Computational Fluid Dynamics simulations. It displays the variation of five common statistics - minimum, first-quartile, median, third-quartile, and maximum - projected onto the three-dimensional spatial sub-space. Visual analysis using the generalized box plot is demonstrated for the unsteady flows past a swept cylinder and a wind turbine.