scholarly journals Numerical Investigation on Radiation Effect in Transpiration Cooling

2021 ◽  
Vol 2097 (1) ◽  
pp. 012011
Author(s):  
Kang Qian ◽  
Taolue Liu ◽  
Fei He ◽  
Meng Wang ◽  
Longsheng Tang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Gas Flow ◽  
Radiation Effect ◽  
Porous Wall ◽  
Radiation Absorption ◽  
Transpiration Cooling ◽  
Coupled Modeling ◽  
High Temperature Gas ◽  
Numerical Strategy

Abstract This paper proposed a numerical strategy which could achieve the coupled modeling and solving of transpiration cooling with external high-temperature gas flow and especially take the radiation effect into account. Based on the numerical strategy, the heat and mass transfer characteristics of the transpiration cooling in a high-temperature gas channel were studied, and the radiation effect and corresponding influence factors were analyzed. The results indicated that the radiative heat flux takes an important role in the heat transfer between the transpiration cooling and external high-temperature gas flow which may reach 40% under the operating condition considered in this work, and the radiation absorption from the coolant is more obvious near the downstream wall. As the wall emissivity increases, the radiation heat transfer in the downstream area of the porous wall is enhanced significantly and thereby the wall temperature there increases, as the result, the uniformity of the temperature distribution on the whole porous wall is improved to some extent.

Friction and Heat Transfer During Injection into a Near-Sonic High-Temperature Gas Flow in a Channel

1997 ◽  
Vol 28 (7-8) ◽  
pp. 438-445
Author(s):  
A. A. Vasil'yev ◽  
O. I. Didenko ◽  
V. F. Vishnyak ◽  
V. N. Panchenko
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Gas Flow ◽  
High Temperature Gas

scholarly journals Conjugate model for heat and mass transfer of porous wall in the high temperature gas flow

2001 ◽  
Vol 17 (3) ◽  
pp. 245-250 ◽  
Author(s):  
A. F. Polyakov ◽  
D. L. Reviznikov ◽  
Shen Qing ◽  
Tang Jinrong ◽  
Wei Shuru
Keyword(s):  
Mass Transfer ◽  
High Temperature ◽  
Heat And Mass Transfer ◽  
Gas Flow ◽  
Porous Wall ◽  
Conjugate Model ◽  
High Temperature Gas

Heat transfer in aerodynamic-tube nozzles with high-temperature gas flow

1978 ◽  
Vol 35 (6) ◽  
pp. 1466-1470
Author(s):  
N. I. Khvostov ◽  
V. E. Chekalin ◽  
A. D. Sukhobokov ◽  
K. N. Skirda
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Gas Flow ◽  
High Temperature Gas

Numerical Investigation of the Effect of Waste Heat Extracting Location on Temperature Distribution

2011 ◽  
Vol 354-355 ◽  
pp. 361-364
Author(s):  
Zhan Xu Tie ◽  
Hai Xia Li ◽  
Xiao Dian Guo
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Gas Flow ◽  
Waste Heat ◽  
Cement Clinker ◽  
Cement Kiln ◽  
Gas Temperature ◽  
Flow And Heat Transfer ◽  
Grate Cooler ◽  
High Temperature Gas

The numerical model was established to simulate the gas flow and heat transfer in cement grate cooler. It is useful to increase the gas temperature when the extracting exit position is close to the cement kiln end. The appropriate position of the extracting high temperature gas is about 5 m far away from the cement clinker inlet.

scholarly journals The Influence of Droplet Dispersity on Droplet Vaporization in the High-Temperature Wet Gas Flow in the Case of Combined Heating

2021 ◽  
Vol 13 (7) ◽  
pp. 3833
Author(s):  
Gintautas Miliauskas ◽  
Egidijus Puida ◽  
Robertas Poškas ◽  
Povilas Poškas
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Phase Change ◽  
Flue Gas ◽  
Gas Flow ◽  
Internal Heat ◽  
Radiation Absorption ◽  
Water Droplets ◽  
Transfer Processes ◽  
Equilibrium Evaporation

The change in the thermal and energy state of the water droplet is defined numerically. The influence of droplet dispersity on the interaction of the transfer processes was evaluated. In influence of the Stefan flow was considered as well. The internal heat transfer of the droplet was defined by the combined heat transfer through effective conductivity and radiation model. The results of the numerical modeling of heat and mass transfer in water droplets in a wet flue gas flow of 1000 °C highlight the influence of the variation in heat transfer regimes in the droplet on the interaction of the transfer processes in consistently varying phase change regimes. The results of the investigation shows that the inner heat convection diminishes intensively in the transitional phase change regime because of a rapid slowdown of the slipping droplet in the gas. The radiation absorption in the droplet clearly decreases only at the final stage of equilibrium evaporation. The highlighted regularities of the interaction between combined transfer processes in water droplets are also valid for liquid fuel and other semi-transparent liquids sprayed into high-temperature flue gas flow. However, a qualitative evaluation should consider individual influence of dispersity that different liquids have.

DISPERSED PHASE VELOCITY IN A HIGH-TEMPERATURE GAS FLOW

2019 ◽  
Vol 23 (4) ◽  
pp. 319-328
Author(s):  
Dmitry V. Nesterovich ◽  
Oleg G. Penyazkov ◽  
Yu. A. Stankevich ◽  
M. S. Tretyak ◽  
Vladimir V. Chuprasov ◽  
...  
Keyword(s):  
High Temperature ◽  
Phase Velocity ◽  
Gas Flow ◽  
Dispersed Phase ◽  
High Temperature Gas

Comparative Study of GaN Growth Process by MOVPE

1999 ◽  
Vol 572 ◽  
Author(s):  
Jingxi Sun ◽  
J. M. Redwing ◽  
T. F. Kuech
Keyword(s):  
High Temperature ◽  
Comparative Study ◽  
Gas Phase ◽  
Residence Time ◽  
Gas Flow ◽  
Flow Sheet ◽  
Flow Zone ◽  
High Quality ◽  
Phase Temperature ◽  
High Temperature Gas

ABSTRACTA comparative study of two different MOVPE reactors used for GaN growth is presented. Computational fluid dynamics (CFD) was used to determine common gas phase and fluid flow behaviors within these reactors. This paper focuses on the common thermal fluid features of these two MOVPE reactors with different geometries and operating pressures that can grow device-quality GaN-based materials. Our study clearly shows that several growth conditions must be achieved in order to grow high quality GaN materials. The high-temperature gas flow zone must be limited to a very thin flow sheet above the susceptor, while the bulk gas phase temperature must be very low to prevent extensive pre-deposition reactions. These conditions lead to higher growth rates and improved material quality. A certain range of gas flow velocity inside the high-temperature gas flow zone is also required in order to minimize the residence time and improve the growth uniformity. These conditions can be achieved by the use of either a novel reactor structure such as a two-flow approach or by specific flow conditions. The quantitative ranges of flow velocities, gas phase temperature, and residence time required in these reactors to achieve high quality material and uniform growth are given.

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