scholarly journals Flow and Heat Transfer Characteristics of High Temperature Gas-Particle Air Jet Flow(Multiphase Flow 2)

2005 ◽  
Vol 2005 (0) ◽  
pp. 319-324
Author(s):  
Hirokazu Nakamura ◽  
Toshihiko Shakouchi
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Multiphase Flow ◽  
Jet Flow ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Air Jet ◽  
High Temperature Gas

Numerical Study on Influencing Factors of Film Cooling on Turbine Blade Leading Edge Under Rotating State

2018 ◽  
Author(s):  
Yiwen Ma ◽  
Haiwang Li ◽  
Meisong Yang ◽  
Min Wu ◽  
Huimin Zhou
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Turbine Blade ◽  
Rotation Number ◽  
Film Cooling ◽  
Leading Edge ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Blade Leading Edge

Engine turbine blades operate at a high speed of rotation and are subjected to high temperature and pressure prevailing gas from the combustion chamber, making the working condition very harsh. In particular, the leading edge of the blade, which is directly subjected to high-temperature gas impacts, is the hottest part of the turbine. Therefore, it is of great importance to improve the protection of the blade leading edge and enhance the understanding of this part of the flow field and temperature field. This paper will focus on the phenomenon of wake deflection and study the film cooling characteristics of the turbine blade under rotating condition. The characteristics of pressure surface and suction surface of the blade are verified by numerical simulation. The contents cover the influence of the film hole diameter, pitch, blowing ratio, rotation number and the development process, the film cooling efficiency on the outflow of coolant film. The result shows that Coriolis force, centrifugal force and secondary flow induced by rotation will change the mainstream flow along the blade, which will lead to changes of pattern concerning the development of the film on the blade surface. In the process of wake development, deflection occurs in different directions at different positions, and the greater the rotation number is, the more obvious the degree of deflection will be. Studying the model with film holes on the leading edge of the blade, these phenomena can be observed along the downstream on the pressure and suction surfaces. Also, models with film holes independently set on the pressure and suction surfaces can be used as proof of these features. At the same time, this paper studies the flow and heat transfer characteristics of the leading-edge gas film under rotating condition and focuses on the influence of rotation on the outflow and the development processes of the wake. The gas film cooling models in rotating state of different film hole diameters and film hole radial spacing will also be compared to further understand the flow and heat transfer characteristics of film cooling on the leading edge of the blade.

Modeling of the Supercritical Steam Generator of MHTGR in Engineering Simulator

2014 ◽  
Author(s):  
Dan Liu ◽  
Jun Sun ◽  
Zhe Sui ◽  
Chun-lin Wei ◽  
Yu-liang Sun
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Steam Generator ◽  
Supercritical Water ◽  
Heat Transfer Characteristics ◽  
Coupling Effects ◽  
Transfer Characteristics ◽  
Helical Tubes ◽  
Steam Generator Model ◽  
High Temperature Gas

The Modular High Temperature Gas-cooled Reactor (MHTGR) could realize higher efficiency and lower costs by developing the multi-modular high temperature gas-cooled reactors combined with supercritical steam turbine unit. The coupling effects among different modules are crucial to the designs and operation analyses of the multi-modular reactors. By establishing the engineering simulator for multi-modular reactors, the coupling effects can be studied and optimized to advance the reactor designs, due to the advantages of real-time calculations and coupled calculations. As key energy transfer equipment, the steam generator is very important to the reactor operation, and focused in the modeling of the engineering simulator system for multi-modular reactors. In this paper, the once-through steam generator consisted of helical coils was modeled and optimized in the vPower integrated simulation platform. From the detailed analyses of the distributions of temperatures, heat flux, and other parameters along the heat transfer tubes, it showed that the steam generator model well presented the supercritical water properties and heat transfer characteristics inside helical tubes. Also, the heat transfer correlations of the supercritical water inside helical tubes were investigated, discussed and also compared to test the uncertainty and influence to the whole steam generator model. And the results indicated that most heat transfer correlations showed similar results and had little effect on the primary side in the steady state operation condition. In future work, the model and heat transfer characteristics of the supercritical steam generator will be further tested in more transients and integrated into complete engineering simulator for multi-module reactors.

scholarly journals Flow and heat transfer characteristics of high temperature continuous rising bubbles

2021 ◽  
pp. 250-250
Author(s):  
Jiarui Xu ◽  
Xiaohui Zhang ◽  
Guangjun Zhang ◽  
Shan Qing
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Bubble Diameter ◽  
Initial Position ◽  
Bubble Velocity ◽  
Liquid Jet ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Bubble Movement

In the movement process of continuous bubbles, different liquid flow state and initial temperature of bubble shave important influence on bubble movement and heat transfer. In this study, the flow and heat transfer characteristics of high temperature bubbles in normal temperature liquid are investigated. The rising process of and temperature of bubbles are studied by numerical simulation and compared with experimental results for verification. The results show that the shape, velocity and temperature of the bubble are affected by the initial position of the bubble. Because the closer the initial position of the bubble is to the bottom of the cylinder, the greater decrease of the bubble aspect ratio (w*),the faster decrease of bubble temperature, and the larger bubble velocity would be. The increase of the bubble diameter would mitigate the influence of liquid jet on the bubble motion. Finally, as the bubble surface tension increases, the liquid jet would have less influence on the bubble movement.

Numerical study on flow and heat transfer characteristics of air-jet cooling system

2018 ◽  
Vol 32 (12) ◽  
pp. 6021-6027 ◽  
Author(s):  
Joo Hyun Moon ◽  
Soyeong Lee ◽  
Jee Min Park ◽  
Jungho Lee ◽  
Daejoong Kim ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Cooling System ◽  
Numerical Study ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Jet Cooling ◽  
Flow And Heat Transfer ◽  
Air Jet
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