Experimental and numerical investigations on mixing flow of film cooling by using twisted holes

Increment in turbine inlet temperature (TIT) is essential for further improvement in thermal efficiency and higher power output of next generation gas turbine engines. Over past decades, significant effort has been made to increase the TIT through development of effective cooling strategies to maint...

Full description

Saved in:

Bibliographic Details
Main Author:	Abdul Wahid, Ammar Fakhir
Format:	Thesis
Language:	English
Published:	2016
Subjects:	TJ Mechanical engineering and machinery
Online Access:	http://eprints.utm.my/id/eprint/78695/1/AmmarFakhirAbdulPFKM2016.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-utm-ep.78695
record_format	uketd_dc
spelling	my-utm-ep.786952018-08-29T07:57:00Z Experimental and numerical investigations on mixing flow of film cooling by using twisted holes 2016-09 Abdul Wahid, Ammar Fakhir TJ Mechanical engineering and machinery Increment in turbine inlet temperature (TIT) is essential for further improvement in thermal efficiency and higher power output of next generation gas turbine engines. Over past decades, significant effort has been made to increase the TIT through development of effective cooling strategies to maintain the blade temperature below the melting point of blade material. Film cooling techniques have been extensively researched to achieve higher TIT. This work was carried out experimentally and numerically to determine the enhancement of film cooling through the use of twisted film cooling hole. The existing combustor test rig was modified to suit experimental investigations of twisted hole film cooling on a flat plate. The Reynolds number was set at Red = 6200 to investigate the turbulent flow regime. The computational fluid dynamics (CFD) software was employed for the numerical simulation of the experimental configurations and other geometries of the twisted cooling hole. High mesh density was applied in the flow domain to capture the significant details of the flow induced by the twisted cooling hole. Three different cooling hole shapes of circular, rectangular and twisted rectangular were investigated under a constant temperature boundary condition and variable thermo-physical properties. The CFD processes were verified through various methods. Simulated results were compared to the experimental measurements giving good agreement and therefore the validation was satisfactory. The results showed that the twisted cooling holes provide a better cooling effectiveness compared to the smooth one. It was found that the cooling effectiveness was enhanced at lower blowing ratios by about 1.1-1.5 times than that of a smooth film cooling hole. This effectiveness enhancement was accompanied by an appreciable increase in heat transfer coefficient in the range of 1.2- 1.6. The improvement in the thermal performance was also found to be in the range of 1.2-1.5. Eventually, the heat transfer coefficient correlation relevant to the parameter studied in the present work was proposed. 2016-09 Thesis http://eprints.utm.my/id/eprint/78695/ http://eprints.utm.my/id/eprint/78695/1/AmmarFakhirAbdulPFKM2016.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:106131 phd doctoral Universiti Teknologi Malaysia, Faculty of Mechanical Engineering Faculty of Mechanical Engineering
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	TJ Mechanical engineering and machinery
spellingShingle	TJ Mechanical engineering and machinery Abdul Wahid, Ammar Fakhir Experimental and numerical investigations on mixing flow of film cooling by using twisted holes
description	Increment in turbine inlet temperature (TIT) is essential for further improvement in thermal efficiency and higher power output of next generation gas turbine engines. Over past decades, significant effort has been made to increase the TIT through development of effective cooling strategies to maintain the blade temperature below the melting point of blade material. Film cooling techniques have been extensively researched to achieve higher TIT. This work was carried out experimentally and numerically to determine the enhancement of film cooling through the use of twisted film cooling hole. The existing combustor test rig was modified to suit experimental investigations of twisted hole film cooling on a flat plate. The Reynolds number was set at Red = 6200 to investigate the turbulent flow regime. The computational fluid dynamics (CFD) software was employed for the numerical simulation of the experimental configurations and other geometries of the twisted cooling hole. High mesh density was applied in the flow domain to capture the significant details of the flow induced by the twisted cooling hole. Three different cooling hole shapes of circular, rectangular and twisted rectangular were investigated under a constant temperature boundary condition and variable thermo-physical properties. The CFD processes were verified through various methods. Simulated results were compared to the experimental measurements giving good agreement and therefore the validation was satisfactory. The results showed that the twisted cooling holes provide a better cooling effectiveness compared to the smooth one. It was found that the cooling effectiveness was enhanced at lower blowing ratios by about 1.1-1.5 times than that of a smooth film cooling hole. This effectiveness enhancement was accompanied by an appreciable increase in heat transfer coefficient in the range of 1.2- 1.6. The improvement in the thermal performance was also found to be in the range of 1.2-1.5. Eventually, the heat transfer coefficient correlation relevant to the parameter studied in the present work was proposed.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Abdul Wahid, Ammar Fakhir
author_facet	Abdul Wahid, Ammar Fakhir
author_sort	Abdul Wahid, Ammar Fakhir
title	Experimental and numerical investigations on mixing flow of film cooling by using twisted holes
title_short	Experimental and numerical investigations on mixing flow of film cooling by using twisted holes
title_full	Experimental and numerical investigations on mixing flow of film cooling by using twisted holes
title_fullStr	Experimental and numerical investigations on mixing flow of film cooling by using twisted holes
title_full_unstemmed	Experimental and numerical investigations on mixing flow of film cooling by using twisted holes
title_sort	experimental and numerical investigations on mixing flow of film cooling by using twisted holes
granting_institution	Universiti Teknologi Malaysia, Faculty of Mechanical Engineering
granting_department	Faculty of Mechanical Engineering
publishDate	2016
url	http://eprints.utm.my/id/eprint/78695/1/AmmarFakhirAbdulPFKM2016.pdf
_version_	1747818048680624128

Experimental and numerical investigations on mixing flow of film cooling by using twisted holes

Similar Items