Volume 6A: Heat Transfer — Combustors; Film Cooling最新文献

{"title":"Investigations on Cooling Hole Patterns Over a Turbine Endwall for Improving Cooling Effectiveness","authors":"Xing Yang, Qiang Zhao, Hang Wu, Z. Feng","doi":"10.1115/gt2022-82799","DOIUrl":"https://doi.org/10.1115/gt2022-82799","url":null,"abstract":"Redistributions of film hole patterns over the endwall region of a turbine vane are investigated in this work, for providing effective coverage for the entire endwall surface. Air enters the linear cascade with a turbulence intensity of 10.8% that is measured in front of the cascade inlet and exits the cascade passage with an averaged Reynolds number of 5.52 × 105. Three film injection patterns are employed: a baseline scheme in which coolant is injected from twelve pressure-side (PS) and four suction-side (SS) discrete holes as well as an upstream slot, a curtain cooling scheme in which two rows of discrete holes (totally thirteen holes) are included in the PS region at the passage inlet, and a hole-redistributed scheme in which the number of the PS holes is reduced and the PS and SS holes are redistributed. Film cooling effectiveness over the endwalls cooled by the three injection patterns is measured using the pressure-sensitive paint (PSP) technique for a density ratio of 1.5 and typical coolant flow rates found in a real engine. Additionally, aerodynamic data is measured by a five-hole probe at the cascade exit to demonstrate the effects of the injection from different hole patterns on flow fields throughout the cascade passage. Comparisons among the three hole patterns reveal that by increasing coolant rates, cooling effectiveness from the slot injection is significantly increased while that from the curtain injection upstream the passage inlet and hole injection within the passage is slightly varied. Although the slot injection is an effective cooling source, it leaves the PS region of the endwall passage uncovered, which can be well alleviated by using the curtain cooing instead of the PS hole injection. Overall, the curtain cooling provides better cooling effectiveness at an equal or even lower coolant flow rate, compared with the baseline configuration, and the hole-redistributed scheme generates better local cooling performance.","PeriodicalId":267158,"journal":{"name":"Volume 6A: Heat Transfer — Combustors; Film Cooling","volume":"187 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127012884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Film Cooling Hole Shape Effects on Turbine Blade Heat Transfer – Part II: Effects of Mass Flow Rate and Unsteadiness","authors":"Spencer J. Sperling, Louis E. Christensen, Randall M. Mathison, H. Aksoy, Jong-Shang Liu, Jeremy B. Nickol","doi":"10.1115/gt2022-78245","DOIUrl":"https://doi.org/10.1115/gt2022-78245","url":null,"abstract":"\u0000 To provide a detailed analysis of film cooling in a turbine environment, this study incorporates experimental and computational research performed on a rotating high pressure turbine stage. The turbine blades include rows of three different film cooling hole shapes investigated at several different cooling mass flow rates supplied to the rotor. Film cooling hole shapes include round, fan, and advanced anti-vortex shapes, and the performance of these cooling systems installed on the rotating blades are evaluated on time-averaged and unsteady bases.\u0000 Film cooling hole shape and coolant mass flow provide different cooling benefits in different areas of the blade. Across the pressure surface, leading edge, and suction surface, advanced film cooling holes show the most response to changing coolant mass flow, and typically have the highest film effectiveness at the highest film cooling flow rate.\u0000 Film cooling jets experience similar motions regardless of hole shape. Unsteady pressure gradients across the film cooling hole outlets on the pressure surface cause cooling jet motion. Fan and Advanced shaped holes cause lateral spread of cooling gas on a steady basis, and due to the increased lateral spread, a larger region on the pressure surface receives consistent film coverage. On a time-average basis, this results in much more lateral spread and increased film coverage for shaped film cooling holes.\u0000 The results of this study help identify the performance of shaped film cooling holes in turbine environments. The response of different hole shapes to unsteadiness has a significant impact on the time average film cooling coverage. Additionally, the hole shapes respond differently to increased levels of coolant mass flow rate and provide different degrees of film cooling coverage on different parts of the blade. An increased understanding and appreciation of the unsteady performance of various film cooling geometries is a foundational piece of continued technology development.","PeriodicalId":267158,"journal":{"name":"Volume 6A: Heat Transfer — Combustors; Film Cooling","volume":"81 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115049079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}