Coupled Heat Transfer Simulations of Air-Cooled Turbines with an Algebraic Transition Model

2012 ◽  
Vol 455-456 ◽  
pp. 1153-1159
Author(s):  
Qiang Wang ◽  
Zhao Yuan Guo ◽  
Guo Tai Feng
2012 ◽  
Vol 455-456 ◽  
pp. 1153-1159
Author(s):  
Qiang Wang ◽  
Zhao Yuan Guo ◽  
Guo Tai Feng

The investigation was to study the effect of laminar-turbulent transition on predicting thermal load of vane. The Abu-Ghannam and Shaw (AGS) algebraic transition model was applied in the coupled solver, HIT3D. Then the solver was employed to carry out coupled heat transfer simulations, and the test case was 5411 run of NASA0-MARKⅡ vane, a high-pressure turbine vane. The results shown that AGS model was able to predict the transition process in the boundary layer near the vane, and that the simulation with such model leads to thermal load agreeing well the measured one. Then the developed solver was applied to predict a low-pressure vane, and the results shown that CHT simulation with full turbulence model would predict higher thermal load than that with transition model.


Author(s):  
R. E. Mayle ◽  
K. Dullenkopf

A theory for transition from laminar to turbulent flow as the result of unsteady, periodic passing of turbulent wakes in the free stream is developed using Emmons’ transition model. Comparisons made to flat plate boundary layer measurements and airfoil heat transfer measurements confirm the theory.


2011 ◽  
Vol 52-54 ◽  
pp. 1057-1061
Author(s):  
Tao Nie ◽  
Wei Qiang Liu

To obtain temperature distribution in regenerative-cooled liquid propellant rocket nozzle quickly and accurately, three-dimensional numerical simulation employed using empirical formulas. A reduced one-dimensional model is employed for the coolant flow and heat transfer, while three dimensional heat transfer model is used to calculate the coupling heat transfer through the wall. The geometrical model is subscale hot-firing chamber. The numerical results agree well with experimental data, while temperature field in nozzle obtained. In terms of computing time and accuracy of results, this method can provide a reference for optimization design and performance estimation.


2013 ◽  
Vol 17 (4) ◽  
pp. 1093-1106 ◽  
Author(s):  
Soraya Trabelsi ◽  
Wissem Lakhal ◽  
Ezeddine Sediki ◽  
Mahmoud Moussa

Combined convection and radiation in simultaneously developing laminar flow and heat transfer is numerically considered with a discrete-direction method. Coupled heat transfer in absorbing emitting but not scattering gases is presented in some cases of practical situations such as combustion of natural gas, propane and heavy fuel. Numerical calculations are performed to evaluate the thermal radiation effects on heat transfer through combustion products flowing inside circular ducts. The radiative properties of the flowing gases are modeled by using the absorption distribution function (ADF) model. The fluid is a mixture of carbon dioxide, water vapor, and nitrogen. The flow and energy balance equations are solved simultaneously with temperature dependent fluid properties. The bulk mean temperature variations and Nusselt numbers are shown for a uniform inlet temperature. Total, radiative and convective mean Nusselt numbers and their axial evolution for different gas mixtures produced by combustion with oxygen are explored.


1992 ◽  
Vol 32 (4) ◽  
pp. 600-607 ◽  
Author(s):  
A. M. Grishin ◽  
A. N. Golovanov ◽  
A. S. Yakimov

1994 ◽  
Author(s):  
K. Funazaki

Measurements of wake-affected heat transfer distributions on a flat plate are made by use of a wake generator that consists of a rotating disk and several types of circular cylinders. The main purpose of this study is to construct a wake-induced transition model in terms of an intermittency factor, considering the evolution of the wake-induced turbulent region, a so-called turbulent patch in a distance-time diagram. A comparison between the proposed transition model and the measured heat transfer data reveals that the transition model yields good agreement with the measured data of all test conditions in this study.


2014 ◽  
Vol 924 ◽  
pp. 329-335 ◽  
Author(s):  
Cong Hang Li ◽  
Shi Chen Jiang ◽  
Zheng Ping Yao ◽  
Song Sheng ◽  
Xin Jian Jiang ◽  
...  

Based on the nanoporous network structure features of silica aerogel, the gas-solid coupled heat transfer model of silica aerogel is analyzed, and the calculation formulas of the gas-solid coupled, the gas thermal conductivity and the heat radiation within the aerogel are derived. The thermal conductivity of pure silica aerogel is calculated according to the derived heat transfer model and is also experimentally measured. Moreover, measurements on the thermal conductivities of silica aerogel composites with different densities at ambient conditions are performed. And finally, a novel design of silica aerogel based integrated structure and thermal insulation used for withstanding the harsh thermal environment on the Martin surface is presented.


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