Influence of Cooling Fluid Parameter on the Fluid Flow and End Part Temperature in End Region of a Large Turbogenerator

2016 ◽  
Vol 31 (2) ◽  
pp. 466-476 ◽  
Author(s):  
Jichao Han ◽  
Baojun Ge ◽  
Dajun Tao ◽  
Weili Li
1995 ◽  
Vol 7 (3) ◽  
pp. 689-704 ◽  
Author(s):  
Santanu Kumar Bhowmik ◽  
Sοmnath Dasgupta ◽  
Stephan Hoernes ◽  
Prasanta Kumar Bhattacharva

2016 ◽  
Vol 155 ◽  
pp. 1-7 ◽  
Author(s):  
Sung-Jin Cho ◽  
Bo-Seung Kim ◽  
Dong-Ki Min ◽  
Yeong-suk Cho ◽  
Jun-hong Park

Author(s):  
Dieter E. Bohn ◽  
Tom Heuer ◽  
Karsten A. Kusterer

Film-cooling has become a widely used cooling method in present day gas turbines. Cooling gas ejection at the leading edge serves to protect the entire vane surface from contact with the hot gas. With doing this, material temperatures are reduced in order to guarantee an economically acceptable life span of the vane. This paper describes the application of a numerical method for the conjugate calculation of internal and external fluid flows and the heat transfer in and through the blade walls of a film-cooled turbine guide vane. The advantage of this approach is that it is possible to predict fluid flow properties and wall temperatures without the need for additional heat transfer conditions or temperature conditions at the external surfaces of the vane. This is a great advantage because the desired data are either unknown or not available for the calculation in the design process of new cooled blades or vanes. In a complete calculation of external and internal flows, no additional boundary conditions at the internal surfaces of the cooling geometry are needed either. Another advantage is the interaction of fluid flow and heat transfer which is taken into account by the conjugate calculation. In the 3-D numerical experiment to be presented, the influence of leading edge cooling fluid ejection on the temperature distribution in the vane material is investigated. The cooling fluid is ejected through two slots at the leading edge. The calculations are performed for three blowing ratios in order to investigate the efficiency of the cooling method. Realistic temperature ratios of cooling-fluid flow and main flow are considered. Such information is very useful in the aero thermal design process of new cooling configurations, since the amount of experimental work can be minimized. The results show the influence of complex 3-D flow phenomena (e.g. passage vortex) on the cooling fluid distribution on the vane surface as a function of the chosen blowing factor. Due to the influence of the passage vortex, the cooling fluid is displaced and leaves the vane surface near the side-wall uncovered against the hot gas. Furthermore, cooling fluid displacement on the pressure side according to the ejection slot geometry leads to another unprotected region on the vane surface. These effects have severe consequences on the thermal load of the vane and can reduce its life span.


2008 ◽  
Vol 271 (1) ◽  
pp. 38-47 ◽  
Author(s):  
Marcelo Esposito ◽  
Claudia Sayer ◽  
Ricardo A. F. Machado ◽  
Pedro H. H. Araújo

2019 ◽  
Vol 13 (1) ◽  
pp. 8
Author(s):  
Azwinur Azwinur ◽  
Zulkifli Zulkifli

Heat exchangers or heat exchangers are tools used to change the temperature of the fluid or change the fluid phase by exchanging heat with another fluid. In a heat exchanger, the ability to exchange heat is largely determined by the type of fluid flow and fluid passing through the heat exchanger. The use of heat exchangers in the field of drying is now a necessity to overcome the problems of drying productivity. The purpose of this study was carried out to determine the effectiveness of the heat exchanger experimentally based on directional flow by comparing construction using baffle and without using baffle in an effort to optimize the drying system. The research method was carried out by fabricating 2 units of heat exchangers and by field testing. The test data obtained are the input and output temperatures of the heating fluid flow and cooling fluid flow and flow velocity. Based on preliminary research data shows that the use of baffle affects the increase in temperature on the heat exchanger, where at the fresh air outlet that does not use baffle produces a temperature of 72oC while the baffle produces 88oC with the Log Mean Temperature Difference heat exchanger without using a baffle higher than heat exchanger that uses a baffle guide blade. This can illustrate that the smaller heat losses are wasted so that the absorption of heat by the reverse system will be higher.


Author(s):  
Carlos A. Rubio-Jime´nez ◽  
Jesu´s Garci´a-Gonza´lez ◽  
Abel Herna´ndez-Guerrero ◽  
Daniela Popescu

In this work a steady state numerical analysis of the capillary effects in channels of a microscopic scale with rectangular cross section is presented. The diameter range under analysis falls on the microchannels classification. The velocities of the fluid flow satisfy the condition We<<Re, necessary and sufficient condition to guarantee that the capillary effects are present in the fluid flow in the channel. Water is used as the cooling fluid. A constant heat flux is applied at the heat sink bottom wall with a rating typical of the generated heat flow in current electronics high-tech devices. The results of thermal resistance are compared with the experimental results of Tuckerman, and the friction coefficient is compared with Peng and Peterson experiments, showing a good approximation when the capillary effects are considered in the numerical solution at lower Reynolds numbers.


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