Effects of dimensional wall temperature on velocity-temperature correlations in supersonic turbulent channel flow of thermally perfect gas

2019 ◽  
Vol 62 (6) ◽  
Author(s):  
XiaoPing Chen ◽  
XinLiang Li ◽  
ZuChao Zhu
Keyword(s):  
Channel Flow ◽  
Wall Temperature ◽  
Turbulent Channel Flow ◽  
Perfect Gas ◽  
Temperature Correlations

Comparative study of Reynolds stress budgets of thermally and calorically perfect gases for high-temperature supersonic turbulent channel flow

2018 ◽  
Vol 233 (11) ◽  
pp. 4222-4234 ◽  
Author(s):  
Xiaoping Chen ◽  
Hua-Shu Dou ◽  
Qi Liu ◽  
Zuchao Zhu ◽  
Wei Zhang
Keyword(s):  
High Temperature ◽  
Reynolds Stress ◽  
Channel Flow ◽  
Velocity Gradient ◽  
Vibrational Energy ◽  
Turbulent Channel Flow ◽  
Mean Flow ◽  
Perfect Gas ◽  
Critical Position ◽  
Stress Budgets

To study the Reynolds stress budgets, direct numerical simulations of high-temperature supersonic turbulent channel flow for thermally perfect gas and calorically perfect gas are conducted at Mach number 3.0 and Reynolds number 4800 combined with a dimensional wall temperature of 596.30 K. The reliability of the direct numerical simulation data is verified by comparison with previous results ( J Fluid Mech 1995, vol. 305, pp.159–183). The effects of variable specific heat are important because the vibrational energy excited degree exceeds 0.1. The viscous diffusion, pressure–velocity gradient correlation, and dissipation terms in the Reynolds stress budgets for TPG, except the streamwise component, are larger than those for calorically perfect gas close to the wall. Compressibility-related term decreases when thermally perfect gas is considered. The major difference for both gas models is mainly due to variations in mean flow properties. Inter-component transfer related to pressure–velocity gradient correlation term can be distinguished into inner and outer regions, whose critical position is approximately 16 for both gas models.

Velocity–temperature correlations in high-temperature supersonic turbulent channel flows for two gas models

2019 ◽  
Vol 33 (21) ◽  
pp. 1950247
Author(s):  
Junming Zhang ◽  
Xiaoping Chen ◽  
Yi Li
Keyword(s):  
High Temperature ◽  
Turbulent Channel Flow ◽  
Channel Flows ◽  
Turbulent Prandtl Number ◽  
Perfect Gas ◽  
Reynolds Analogy ◽  
Turbulent Channel Flows ◽  
The Mean ◽  
Temperature Correlations ◽  
Better Than

Velocity–temperature correlations in a high-temperature supersonic turbulent channel flows, including thermally perfect gas (TPG) and calorically perfect gas (CPG), are investigated based on the direct numerical simulation database [Chen et al., J. Turbul. 19 (2018) 365] to study the gas model effects. The results show that in fully developed turbulent channel flow, the Reynolds analogy factor remains close to 1.2 for both gas models. The “recovery enthalpy” is better than Walz’s equation to connect the mean stream-wise velocity with mean static temperature because it is independent with gas models. The modified strong Reynolds analogy for TPG is more accurate scaling than that for CPG, and the turbulent Prandtl number is insensitive to gas models. In addition, the influence of gas model on the probability density functions of stream-wise velocity and static temperature concentrate on the corresponding right tails.

scholarly journals Sensitivity analysis of heat transfers in an asymmetrically heated turbulent channel flow

2021 ◽  
Vol 321 ◽  
pp. 03001
Author(s):  
Martin David ◽  
Adrien Toutant ◽  
Françoise Bataille
Keyword(s):  
Heat Flux ◽  
Sensitivity Analysis ◽  
Channel Flow ◽  
Wall Temperature ◽  
Turbulent Channel Flow ◽  
Uncertainty Management ◽  
Bulk Temperature ◽  
Cold Wall ◽  
Heat Transfers ◽  
Global Uncertainty

A sensitivity analysis of heat transfers in an asymmetrically heated turbulent channel flow is performed using a dedicated heat transfer correlation. The investigated correlation is developed to study the heat transfers between the fluid and the wall in gas-pressurized solar receivers of concentrated solar power tower. The working conditions correspond to high-temperature levels and high heat fluxes. The correlation of the Nusselt number depends on five parameters: the Reynolds number, the Prandtl number, the fluid temperature, the hot and cold wall temperatures. We investigate the sensitivity of the heat flux to the wall and fluid temperatures. The results obtained with the global uncertainty management are compared to direct computations of the errors of measurement. In the global uncertainty management, the heat flux sensitivity is studied with the Taylor expansion of the function. This method assumes the quasilinearity and the quasi-normality of the function; therefore, only small variations of parameters are computed. The study points out the importance of the temperature measurement accuracy for the heat flux evaluation in asymmetrically heated turbulent channel flow. In particular, the results show that the cold wall heat flux is very sensitive to the variations of the cold wall temperature and the bulk temperature of the fluid. The hot wall is less influenced by the temperature variations than the cold wall. The global uncertainty management produces satisfying results on the prediction of the error linked to the uncertainties on bulk temperature. Nevertheless, the hot and cold wall temperature uncertainty propagation are poorly estimated by the method.

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