Experimental investigations of the effect of scheme exit height and double row injection on the film cooling performance of a micro tangential jet scheme, part II: Suction side

O. Hassan, Ibrahim Hassan

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

This paper presents experimental investigations of the effect of scheme exit height and double jet injection on the film cooling performance of a Micro-Tangential-Jet (MTJ) scheme on the suction side of a gas turbine vane using the transient Thermochromic Liquid Crystal (TLC) technique. In part I of the present paper the investigations over the pressure side are presented. The MTJ scheme is a micro-shaped scheme designed so that the micro-sized secondary jet is supplied tangentially to the vane surface. In order to investigate the effect of scheme exit height, one row of the MTJ scheme with exit height of 1.5 hole diameters was investigated and compared with the case of 1.0 hole diameter scheme exit height. Meanwhile, to investigate the effect of double injection, one row of the MTJ scheme in staggered arrangement with one row of fan-shaped scheme was investigated. The investigations were conducted at a blowing ratio, calculated based on the scheme exit area, ranging from 0.25 to 0.625. The average density ratio during the investigations was 0.93, and the Reynolds Number was 1.4E+5, based on the free stream velocity and the main duct hydraulic diameter. The pitch to diameter ratio of the cooling holes is 6.5, and the turbulence intensity during all investigations was 8.5%. The increase in the MTJ scheme exit height did not result in significant change in the Mach number distribution. Moreover, increasing the scheme exit height resulted in enhanced effectiveness performance. The enhanced effectiveness was accompanied with Heat Transfer Coefficient (HTC) ratio augmentation as well. As a result, a reduction in the Net Heat Flux Reduction (NHFR) accompanied increasing the scheme exit height from 1.0 to 1.5 hole diameters. Besides, adding a row of shaped schemes in front of the MTJ scheme result in significant effectiveness reduction, compared to the case of single row injection. The latter was attributed to the presence of the shaped scheme inclination angle that result in enhanced secondary stream loss due to the perpendicular momentum component to the vane surface accompanying the shaped scheme secondary jet.

Original languageEnglish
Title of host publicationASME 2015 Power Conference, POWER 2015, collocated with the ASME 2015 9th International Conference on Energy Sustainability, the ASME 2015 13th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2015 Nuclear Forum
PublisherAmerican Society of Mechanical Engineers (ASME)
Volume2015-January
ISBN (Electronic)9780791856604
DOIs
Publication statusPublished - 2015
EventASME 2015 Power Conference, POWER 2015, collocated with the ASME 2015 9th International Conference on Energy Sustainability, the ASME 2015 13th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2015 Nuclear Forum - San Diego, United States
Duration: 28 Jun 20152 Jul 2015

Other

OtherASME 2015 Power Conference, POWER 2015, collocated with the ASME 2015 9th International Conference on Energy Sustainability, the ASME 2015 13th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2015 Nuclear Forum
CountryUnited States
CitySan Diego
Period28/6/152/7/15

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Keywords

  • Effectiveness
  • Film cooling
  • Gas turbines
  • Heat transfer coefficient
  • Micro film cooling
  • Net heat flux reduction
  • Tangential injection

ASJC Scopus subject areas

  • Mechanical Engineering
  • Energy Engineering and Power Technology

Cite this

Hassan, O., & Hassan, I. (2015). Experimental investigations of the effect of scheme exit height and double row injection on the film cooling performance of a micro tangential jet scheme, part II: Suction side. In ASME 2015 Power Conference, POWER 2015, collocated with the ASME 2015 9th International Conference on Energy Sustainability, the ASME 2015 13th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2015 Nuclear Forum (Vol. 2015-January). American Society of Mechanical Engineers (ASME). https://doi.org/10.1115/POWER201549132