A parametric study to simulate the non‐Newtonian turbulent flow in spiral tubes (original) (raw)
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A review on Heat transfer & Flow Characteristics in Spiral tubes
Fluid flows via path curvature pipe can increase the efficiency of transfer of heat. Spiral coils are frequently used for the heat exchangers, electronic cooling, chemical reactors, food industry, health industry and so on. They are compact & their heat transfer rate is much higher as especially in comparison to straight tubes of the very same length.. It is a well-known fact that heat transfer in Spiral coil is higher than in straight pipe. This study summarizes and discusses critically the studies published in the literature about the characteristics of pressure drop & flow in spirally coiled tubes. Consequently, the aim of this analysis is to provide educational and industrial researchers with a realistic overview of the related correlations and supporting Method for measuring the characteristic of pressure drop & flow in Spiral pipe tubes.
2022
The curved tubes have various engineering applications in various thermo-hydraulic systems. The detailed parametric thermo-hydraulic study of conical spiral tubes is a lesser explored domain. In the present study using the numerical simulation method, the heat transfer characteristics of conical spiral tube for the turbulent flow is studied. The influence of Reynolds number (in the range of 10 4 to 10 5) and of geometrical parameters such as cone taper angle and curvature of conical spiral tube on the local and total heat transfer is investigated. The CFD results show that the local circumferential and total coil heat transfer increased with the increase in cone taper angle and Reynolds number. The fully developed Nusselt number is found to be achieved by angular length of 210⁰ from inlet plane in the coil.
International Journal of Heat and Mass Transfer, 2007
Effect of curvature ratios on the heat transfer and flow developments in the horizontal spirally coiled tubes are investigated. The spirally coiled tube is fabricated by bending a 8.00 mm diameter straight copper tube into a spiral-coil of five turns. The spirally coiled tube with three different curvature ratios of 0.02, 0.04, 0.05 under constant wall temperature are tested. Cold water entering the innermost turn flows along the spiral tube and flows out at the outermost turn. The turbulent flow and heat transfer developments are simulated by using the k-e standard turbulence model. A finite volume method with an unstructured nonuniform grid system is employed for solving the model. The simulated results are validated by comparing with the present experiment. The predicted results for the convective heat transfer and flow characteristics are reasonable agreement with the experiments. The centrifugal force has significant effect on the enhancements of heat transfer and pressure drop. In addition, due to this force, the heat transfer and pressure drop obtained from the spirally coiled tube are higher than those from the straight tube.
CFD Investigation of Convective Heat Transfer in Spiral Coiled tubes
2021
Heat transfer efficiency will improve when fluid passes via pathway curvature pipes. It is generally known that heat transmission in a spiral coil is greater than in a straight pipe. The detailed characteristic of Heat transfer & flow of fluid is not shown in this report. This report brings out cfd analysis of how Improves transfer of heat & drop in pressure. With the help of this analysis, we will be able to predict Transferring heat & pressure drop inside a Spiral tube. CFD simulation is carried out for Spiral coils by varying coil parameters such as (i) diameter of tube (ii) Pitch of coil (iii) Number of Turns and their effects on heat transmission have been investigated. Since there is no Published Numerical, Analytical and Experimental details about spiral coils systems. In this report the laminar of flow pressure drop & Characteristics of transfer heat from spiral coil systems will be investigated with commercially available ANSYS FLUENT CFD package. The influences of paramete...
Of Heat Transfer and Pressure Drop Augmentation for Laminar Flow in Spirally Enhanced Tubes
2000
The effect of the internal helical ridging on the heat transfer coefficient and friction factor is experimentally investigated for laminar internal flow of a Newtonian fluid in the case of uniform wall heat flux. Five different geometries are considered. The results are compared with the results of previous investigations and with the predictions for the smooth tube in order to point out the heat transfer enhancement and the friction factor increase in the laminar flow field.
Laminar fluid flow and heat transfer through a circular tube having spiral ribs and twisted tapes
Experimental Thermal and Fluid Science, 2015
The experimental friction factor and Nusselt number data for laminar flow of viscous oil through a circular duct having integral spiral rib roughness and fitted with twisted tapes with oblique teeth have been presented. Predictive friction factor and Nusselt number correlations have also been presented. The thermohydraulic performance has been evaluated. The major findings of this experimental investigation are that the twisted tapes with oblique teeth in combination with integral spiral rib roughness perform significantly better than the individual enhancement technique acting alone for laminar flow through a circular duct up to a certain value of fin parameter.
Numerical simulation of thermally developing turbulent flow through a cylindrical tube
International Journal On Interactive Design And Manufacturing (ijidem), 2019
A numerical study was conducted using the finite difference technique to examine the mechanism of energy transfer as well as turbulence in the case of fully developed turbulent flow in a circular tube with constant wall temperature and heat flow conditions. The methodology to solve this thermal problem is based on the energy equation a fluid of constant properties in an axisymmetric and two-dimensional stationary flow. From the mathematical side, a numerical technique for solving the problem of fluid-structure interaction with a fully developed turbulent incompressible Newtonian flow is described. The global equations and the initial and boundary conditions acting on the problem are configured in dimensionless form in order to predict the characteristics of the turbulent fluid flow inside the tube. Using Thomas' algorithm, a program in FORTRAN was developed to numerically solve the discretized form of the system of equations describing the problem. Finally, using this elaborate program, we were able to simulate the flow characteristics, for changing parameters such as Reynolds, Prandtl and Peclet numbers along the pipe to obtain the important thermal model. These are discussed in detail in this work. Comparison of the results to published data shows that results are a good match to the published quantities. Keywords Finite difference method • Nusselt number • Fully developed turbulent flow • Reynolds number • Pipe flow List of symbols A j Coefficient in Eq. (36) B j Coefficient in Eq. (36) C j Coefficient in Eq. (36) C p Specific heat at constant pressure (J kg −1 K −1) C 1 , C 2 k-ε model constants D Inner diameter (m) D j Coefficient in Eq. (36) E Inner energy (J kg −1), dimensionless variable f Fanning friction factor F Function k Turbulent kinetic energy (J kg −1) L Tube length (m) M Tridiagonal matrix of dimensions (N × N) B Ali Belhocine
Isothermal laminar fluid flow in spiral tube coils
Heat and Mass Transfer, 2018
An experimental study is performed to measure pressure drop for Newtonian fluid flow through copper spirals of different geometries. The experimental friction factors obtained are presented and correlated with the different geometrical parameters of the spiral coils. Four spiral coils with D i D À Á ratio ranging from 0.0178 to 0.028 and L D i ratio ranging from 527.5 to 2110.169 are investigated. A new dimensionless number, the R number is introduced which is found to characterize the fluid flow phenomenon in spiral coil tubes. An innovative approach to correlate Dean and R numbers with friction factor data of variable curvature coils for laminar flow regime is presented for the first time. The study will prove useful to bridge the gap between the straight tube flow and curved coil flow based on a single dimensionless number. Nomenclature a, b Correlation constants c, d Correlation constants a1, b1 Correlation constants c1, d1 Correlation constants a2, b2 Correlation constants c2, d2 Correlation constants a3, b3 Correlation constants c3, d3 Correlation constants C, φ, Correlation constants n1, n2 Correlation constants C p Specific heat at constant pressure (J/kg K) D Average diameter of curvature for a spiral (m) D co Maximum diameter of coil (m) D ci Minimum diameter of coil (m) D i Inside diameter of spiral coil tube (m) D o Outside diameter of Spiral Coil tube (m)