HEAT TRANSFER CHARACTERISTICS AND BOUNDARY LAYER DEVELOPMENT ABOUT HEATING AND COOLING ROTATING BLUNT BODIES AT SUPERSONIC SPEEDS

1982 ◽  
Author(s):  
David C. Chou ◽  
James A. Kalina
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Heating And Cooling ◽  
Boundary Layer Development ◽  
Blunt Bodies ◽  
Layer Development

Numerical Simulation of Turbine Blade Boundary Layer and Heat Transfer and Assessment of Turbulence Models

1997 ◽  
Vol 119 (4) ◽  
pp. 794-801 ◽  
Author(s):  
J. Luo ◽  
B. Lakshminarayana
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Reynolds Number ◽  
Low Reynolds Number ◽  
Turbulence Models ◽  
Navier Stokes ◽  
Bypass Transition ◽  
Boundary Layer Development ◽  
Low Reynolds ◽  
Layer Development

The boundary layer development and convective heat transfer on transonic turbine nozzle vanes are investigated using a compressible Navier–Stokes code with three low-Reynolds-number k–ε models. The mean-flow and turbulence transport equations are integrated by a four-stage Runge–Kutta scheme. Numerical predictions are compared with the experimental data acquired at Allison Engine Company. An assessment of the performance of various turbulence models is carried out. The two modes of transition, bypass transition and separation-induced transition, are studied comparatively. Effects of blade surface pressure gradients, free-stream turbulence level, and Reynolds number on the blade boundary layer development, particularly transition onset, are examined. Predictions from a parabolic boundary layer code are included for comparison with those from the elliptic Navier–Stokes code. The present study indicates that the turbine external heat transfer, under real engine conditions, can be predicted well by the Navier–Stokes procedure with the low-Reynolds-number k–ε models employed.

Some Boundary Layer-Porous Wall Coupling Effects in Laminar Flows With Surface Injection

1970 ◽  
Vol 92 (3) ◽  
pp. 257-266
Author(s):  
D. A. Nealy ◽  
P. W. McFadden
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Heat Balance ◽  
Transfer Problem ◽  
Porous Wall ◽  
Laminar Flows ◽  
Stream Velocity ◽  
Axial Conduction ◽  
Boundary Layer Development ◽  
Layer Development

Using the integral form of the laminar boundary layer thermal energy equation, a method is developed which permits calculation of thermal boundary layer development under more general conditions than heretofore treated in the literature. The local Stanton number is expressed in terms of the thermal convection thickness which reflects the cumulative effects of variable free stream velocity, surface temperature, and injection rate on boundary layer development. The boundary layer calculation is combined with the wall heat transfer problem through a coolant heat balance which includes the effect of axial conduction in the wall. The highly coupled boundary layer and wall heat balance equations are solved simultaneously using relatively straightforward numerical integration techniques. Calculated results exhibit good agreement with existing analytical and experimental results. The present results indicate that nonisothermal wall and axial conduction effects significantly affect local heat transfer rates.

Study of Heat Transfer Characteristics in the Boundary Layer of a Visco-Elastic Fluid Under Varying Influencing Parameters

2007 ◽  
Author(s):  
P. Anuradha ◽  
S. Krishnambal
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Numerical Study ◽  
Numerical Technique ◽  
Heat Transfer Characteristics ◽  
Elastic Fluid ◽  
Transfer Characteristics ◽  
Dimensional Parameters ◽  
Influencing Parameters ◽  
Sheet Stretching

The heat transfer characteristics of a visco-elastic fluid within the boundary layer formed by the passage of a sheet stretching at a uniform rate through it are studied under varying influencing parameters using a numerical technique. The influence of considering or ignoring elastic deformation in the thermal analysis is studied in the presence of chosen values of non-dimensional parameters like Prandtl number (Pr) and Eckert number (E). Two cases of sheet surface conditions are considered — (i) PST case involving prescribed surface temperature and (ii) PHF case involving prescribed heat flux at the surface. The results of this numerical study are diagrammatically represented with appropriate conclusions drawn on the influence of the above parameters considered in isolation or together. The trend of results is seen to agree well with those of other researchers who used other solution techniques. A judious choice of the above two principal non-dimensional parameters is suggested for application to a cooling process typical of a polymer extrusion industry.

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