Date of Award
Master of Science in Aeronautical Engineering
Department of Aeronautics and Astronautics
James L. Rutledge, PhD.
Effective film cooling relies on the performance of the selected cooling hole shape and placement of the holes on the surface of the blade. To test each holes effectiveness, large scale, low-temperature testing has been used to reduce cost and complexity. The resulting quantity from this testing is called the adiabatic effectiveness (n). The adiabatic effectiveness can then scaled up to engine operating conditions to predict how the selected film cooling hole will perform. This process is complicated by the nonlinear variation of gas properties between coolant and freestream conditions as well as between the experimental and engine conditions. In this study, various gases were used as coolant to simulate changes in gas properties as one might have between experimental and engine conditions. It was found that when specific heat is included in the form of a new parameter known as the Advective Capacity Ratio (ACR), adiabatic effectiveness results scale well between different cooling gases. Specifically at low momentum flux ratios, use of ACR produced very similar adiabatic effectiveness profiles between all gases.
DTIC Accession Number
Fischer, Jacob P., "Influence of Coolant Flow Rate Parameters in Scaling Gas Turbine Cooling Effectiveness on a Flat Plate" (2018). Theses and Dissertations. 1768.