Conjugate conduction-convection heat transfer with a high-speed boundary layer

10.2514/3.534 ◽  
1994 ◽  
Vol 8 (2) ◽  
pp. 275-281 ◽  
Author(s):  
Frederick L. Shope
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
High Speed ◽  
Convection Heat Transfer ◽  
Convection Heat ◽  
Conjugate Conduction

Unsteady Natural Convection Heat Transfer Past a Vertical Flat Plate Embedded in a Porous Medium Saturated With Fractional Oldroyd-B Fluid

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Jinhu Zhao ◽  
Liancun Zheng ◽  
Xinxin Zhang ◽  
Fawang Liu ◽  
Xuehui Chen
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Porous Medium ◽  
Natural Convection ◽  
Prandtl Number ◽  
Fractional Derivative ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Elastic Effect

This paper investigates natural convection heat transfer of generalized Oldroyd-B fluid in a porous medium with modified fractional Darcy's law. Nonlinear coupled boundary layer governing equations are formulated with time–space fractional derivatives in the momentum equation. Numerical solutions are obtained by the newly developed finite difference method combined with L1-algorithm. The effects of involved parameters on velocity and temperature fields are presented graphically and analyzed in detail. Results indicate that, different from the classical result that Prandtl number only affects the heat transfer, it has remarkable influence on both the velocity and temperature boundary layers, the average Nusselt number rises dramatically in low Prandtl number, but increases slowly with the augment of Prandtl number. The maximum value of velocity profile and the thickness of momentum boundary layer increases with the augment of porosity and Darcy number. Moreover, the relaxation fractional derivative parameter accelerates the convection flow and weakens the elastic effect significantly, while the retardation fractional derivative parameter slows down the motion and strengthens the elastic effect.

scholarly journals CONJUGATE CONDUCTION-FREE CONVECTION HEAT TRANSFER FROM A HORIZONTAL CYLINDER

2013 ◽  
Vol 36 (2) ◽  
pp. 155-166
Author(s):  
M. K. Bassiouny ◽  
F. M. Mahfouz ◽  
S. A. Wilson ◽  
Gamal H. Badawy
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Convection Heat Transfer ◽  
Horizontal Cylinder ◽  
Convection Heat ◽  
Free Convection Heat ◽  
Conjugate Conduction

Multi-Fidelity Analysis of Acoustic Streaming in Forced Convection Heat Transfer

2019 ◽  
Author(s):  
Tapish Agarwal ◽  
Iman Rahbari ◽  
Jorge Saavedra ◽  
Guillermo Paniagua ◽  
Beni Cukurel
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Turbulent Flow ◽  
Forced Convection ◽  
Parameter Space ◽  
Thermal Boundary Layer ◽  
Acoustic Streaming ◽  
Convection Heat Transfer ◽  
Convection Heat ◽  
Wave Disturbances

Abstract The behavioral characteristics of thermal boundary layer dictate the relative efficiency of forced convection heat transfer. This research effort is related to the detailed analysis of the temporal evolution of thermal boundary layer under periodic excitations. In presence of oscillations, a distinct thin Stokes layer is formed inside the attached boundary layer, which interacts nonlinearly with the mean flow in the near wall region. This interaction leads to modification of temporally averaged flow fields, commonly known as acoustic streaming. As a result, the aero-thermal wall gradients are modified leading to significant changes in wall shear stress and heat flux. However, the small spatial scales and the inherent unsteady nature of streaming has presented challenges for prior numerical investigations, preventing the identification of optimal parameters. In order to address this void in numerical framework, the development of a three-tier numerical approach is presented. As a first layer of fidelity, a laminar model is developed for fluctuations and streaming flow calculations in laminar flows subjected to travelling wave disturbances. This technique is an extension of the Lin’s method to traveling wave disturbances of various speeds (absent of previously employed assumptions), along with inclusion of energy equation. With low computational cost, this level of abstraction is intended to identify the broad parameter space that yield desirable heat transfer alterations. At the next level of fidelity, 2D U-RANS simulations are conducted across both laminar and turbulent flow regimes. This is geared towards extending the parameter space obtained from laminar model to turbulent flow conditions. As the third level of fidelity, temporally and spatially resolved DNS simulations are conducted to simulate the application relevant compressible flow environment. The exemplary findings indicate that in certain parameter space, both enhancement and reduction in heat transfer can be obtained through acoustic streaming. Moreover, the extent of heat transfer modulations is greater than alterations in wall shear, thereby surpassing Reynolds analogy.

Thermal Response Characteristics of Flat Plate Heated by High Temperature and High Speed Flow

2013 ◽  
Vol 448-453 ◽  
pp. 3316-3319
Author(s):  
Chuang Sun ◽  
Yang Zhao ◽  
De Fu Li ◽  
Qing Ai ◽  
Xin Lin Xia
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Flat Plate ◽  
High Speed ◽  
Convection Heat Transfer ◽  
Thermal Response ◽  
Convection Heat ◽  
Convection Heat Transfer Coefficient

According to the view of heat transfer, the process of the fluid flow with high temperature and high speed over a flat plate may be considered as the heat transfer process within a compressible thermal boundary layer. Based on the numerical results of thermal isolation assumption, combining the temperature comparison with modification method, a coupled method of convection heat transfer coefficient with temperature field of the plate is established, and the characteristics of the thermal response for the flat plate is dominated. Take some ribbed plates as instances, the convection heat transfer coefficient and temperature field of the plate are simulated through the provided coupled method. The results show that, not only the position and materials of the plate influence the convection heat transfer coefficient, but also the time.

Sign in / Sign up

Export Citation Format

Share Document