MODELING AND CFD ANALYSIS ON JET NOZZLES (original) (raw)
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CFD Investigation for different nozzle jets
Materials Today: Proceedings, 2017
Nozzle delivers thrust and gives momentum to the aerospace vehicle. Nozzle design is to be developed with respect to the application based on various factors under consideration during evolving of a system design. Specific impulse required is one of the major factors to define nozzle configuration with minimum variation in thrust delivered. As supersonic jet flow leaves the nozzle, it becomes a free shear layer, and action of turbulence dominates flow developments farther downstream. Therefore jet flow contains large interactions with surrounding medium. These combinations include turbulent mixing and compressibility effects such as isentropic expansion and shock. Numerical simulations are performed using commercially available software FLUENT to investigate and understand the performance of conical and scarfed nozzle. CFD Studies carried out for selecting a suitable mesh and selection of suitable turbulence model for computing nozzle jet flow field. Simulations were made using Spalart-Allmaras model and SST model. Based on the results, scarfed nozzle gives relatively low mach number compared to conical nozzle. The scarfed nozzle is preferred due to the missile configuration constraints.
IRJET- CFD ANALYSIS OF CONVERGENT AND DIVERGENT NOZZLE
IRJET, 2020
A nozzle is a very essential device that is used to control character of the fluid. The main purpose of the nozzle is to increase the velocity in one way or another. De Laval nozzle is a converging-diverging nozzle which has the ability to convert the chemical energy (high pressure) into kinetic energy (high velocity and low pressure). De-Laval nozzle has mainly 3 parts such as throat, diverging part, and converging part. Expansion in C-D nozzle has been studied and analyzed by experimentation moreover as numerically by numerous researchers with an objective to optimize the performance beneath given conditions. Within the gift work, supersonic flow through the rocket nozzle has been simulated mistreatment numerical methodology. The analysis has been performed keeping the same input and according to the shape of the nozzle. Our objective is to investigate the best suit nozzle which gives high exit velocity among the different cross-sections considered. The main aim of this paper is to a proper comparison with theoretical data to determine the behavior of fluid during the movement of fluid inside the nozzle. Therefore CFD analysis is being done using ANSYS 16. The paper contains a proper analysis of the convergent-divergent nozzle. Analysis of Mach number and velocity is done inside the nozzle
CFD Analysis of C-D Nozzle compared with Theoretical & Experimental Data
2017
In modern Computational Fluid Dynamic (CFD) Analysis of Convergent-Divergent (C-D) Nozzles, current research has shown that, it is common practice to use either experimental or analytical results to predict the accuracy of the CFD models by comparison of the results. It is also commonly agreed, amongst the literature reviewed, that the CFD modelling software packages available do not accurately model turbulence for applications such as transonic C-D nozzles. This study aims to develop a theoretical approach for calculation of flow properties along the axis of the C-D nozzle based on the fundamental gas dynamic equations. The theoretical analyses is validated by experimental data. Then, the CFD model is used to simulate the experimental cases which are compared with the data from both theoretical analysis and experimental measurements. Then, the validated CFD model can be used for more complex analyses, representing more elaborate flow phenomena such as internal shockwaves and boundary layers. The geometry used in the analytical study and CFD simulations constructed to model the experimental rig. The [1, 2] analytical study is undertaken using isentropic and adiabatic relationships and the output of the analytical study, the 'shockwave location tool', is created. The results from the analytical study are then used to optimise the redesign an experimental rig to for more favorable placement of pressure taps and gain a much better representation of the shockwaves occurring in the divergent section of the nozzle. The results from the CFD model can then be directly compared other results in order to gauge the accuracy of each method of analysis. The validated model can then be used in order to create several, novel nozzle designs which may offer better performance and ease of manufacture and may present feasible improvements to existing high-speed flow applications.
A nozzle is a device that is used to provide the way and direction to gases to come out of the combustion chamber. The nozzle is a device that is used to convert pressure and thermal energy into useful kinetic energy. A rocket nozzle can be used to manage and control the speed flow of pressure and steam being exhausted .rocket nozzle purpose is to convert high pressure, high-temperature gas into a high velocity, low temperature, and pressure. This paper had an analysis of the flow in the nozzle using the software ANSYS 16. The study is being carried out to have knowledge about flow inside the nozzle when the divergent section of the nozzle is being diverted or change to a certain angle using 2-d modeling to carry out the result and effects of the nozzle. The angle will make the effect on all the aspects of nozzle such as Mach number, static pressure, velocity, and temperature. The throat and inlet diameter of supersonic begin remain the same.
Numerical Investigation of the Perfomance of Convergent Divergent Nozzle
2013
The main objective of the work is to analyse the performance and flow characteristics of convergent divergent nozzle and also to compare the numerical values of the two methods i.e "HIT & TRIAL METHOD" AND "ANALYTICAL METHOD". In this paper we have determine the location and strength of normal shock wave in the divergent portion of the nozzle under varying operating conditions and with different nozzle geometry. KEYWORD: Mach number, Sub-sonic, Super-sonic, Sonic, Compressible flow, Throat. I. NTRODUCTION A nozzle is a relatively simple device, just a specially shaped tube through which hot gases flow. However, the mathematics, which describes the operation of the nozzle, takes some careful thought. Nozzles come in a variety of shapes and sizes. Simple turbojets, and turboprops, often have a fixed geometry convergent nozzle as shown on the left of the figure. Turbofan engines often employ a co-annular nozzle. The core flow exits the centre nozzle while the fan fl...
ANALYSIS OF FLOW CHARACTERISTICS OF DE LAVAL NOZZLE
IJRAME PUBLICATIONS, 2022
A nozzle is a relatively simple device that consists of a specifically formed tube that allows hot gases to flow through it. However, the mathematics that describes the nozzle's operation necessitates some thought. Nozzles are available in a wide range of forms and sizes. A fixed geometry convergent nozzle is common on simple turbojets and turboprops. A co-annular nozzle is commonly used in turbofan engines. The core flow exits the central nozzle, while the annular nozzle exits the fan flow. The mixing of the two flows increases thrust, and these nozzles are also quieter than convergent nozzles. A variable geometry convergent-divergent CD nozzle is required for afterburning turbojets and turbofans. The flow in this nozzle first converges down to the smallest area, or throat, before expanding via the divergent segment to the right exit. These nozzles are heavier than fixed geometry nozzles because of the variable geometry, however variable geometry allows more efficient engine running across a larger airflow range than a conventional fixed nozzle. Nozzles are also used in rocket engines to accelerate hot exhaust and generate thrust. A fixed geometry CD nozzle is used in rocket engines, having a significantly greater divergent section than is required for a gas turbine.
IRJET- Modelling and Analysis of a Convergent -Divergent Nozzle
IRJET, 2021
Nozzle is a part of the propulsion system which is used to accelerate the hot gases flowing through it. The nozzle geometry is highly important because it directly affect the overall performance of propulsion system. Also, design of nozzle is an important aspect for achieving the maximum Mach number or supersonic speed. To achieve supersonic speed a type of nozzle called Convergent-Divergent nozzle or otherwise known as the de Laval nozzle or CD nozzle is used which converts the high temperature, high pressure, and low velocity gas into high velocity and low pressure gas at the exit. The main aim of this work is to model Convergent-Divergent nozzle and analyse the variation in flow parameters that are static pressure, velocity, static temperature and Mach number by modifying the nozzle divergent angle, keeping same throat and inlet diameter and by using the optimum convergent angle of 28.5°. Analysis is carried out for divergent angles 5°, 10°, 15° and 20° using computational fluid dynamics software(CFD). CFD results were compared with the theoretical results. Variation in flow parameters at the nozzle outlet is studied so as to find the optimum divergent angle for the optimum convergent angle. By considering the results of all the divergent angles 20° gave maximum Mach number that will lead to improve performance of the nozzle and thereby the power and efficiency of a propulsion system.
CONCEPTS AND CFD ANALYSIS OF DE-LAVAL NOZZLE
Anozzle is a device designed to control the characteristics of fluid. It is mostly used to increase the velocity of fluid. A typical De-Laval nozzle is a nozzle which has a converging part, throat and diverging part. This paper aims at explaining most of the concepts related to De Laval nozzle. In this paper the principle of working of nozzle is discussed. Theoretical analysis of flow is also done at different points of nozzle. The variation of flow parameters like Pressure, Temperature, Velocity and Density is visualized using Computational Fluid Dynamics. The simulation of shockwave through CFD is also done.
In this experimental investigation the work reported is about the influence of control on the flow field in the suddenly expanded duct at low supersonic Mach number. A Convergent-divergent (CD) nozzle was designed and fabricated out of brass material assembled with the suddenly expanded duct which was also made of brass material. At the re-circulation zone, the flow field was controlled by using the micro jets of 1 mm diameter as an orifice and the control was arranged at an interval of 90 degrees at 6.5 mm from the central axis of the main jet. The measured wall pressure distribution was presented for Mach number 1.1 for the duct diameter of 18 mm leading to the area ratio 3.24. The L/D ratio of the duct was varied from 1 to 10, and the nozzle pressure ratio (NPR) considered for the experiments was from 3, 5, 7, 9 and 11. The present results have demonstrated that the micro jets do not influence the flow field in the duct adversely and the flow field remained identical in the presence of control or absence of control.