Computational Benchmarking Gas Turbine Cooling Geometries
PI Mark Ricklick
The accuracy of the simulation of gas turbine component temperatures relies heavily on the selection of appropriate modeling parameters. The focus of this project is the research and development of these parameters, through the comparison to experimental data-sets.
Gas turbines are an intricate part of today’s society, powering aircraft and cities. The ability to accurately predict component temperatures through cost-effective Reynolds-Averaged-Navier-Stokes (RANS) simulation directly contributes to the engine efficiency and durability. The increase in turbine inlet gas temperatures directly contribute to improvements in efficiency, exploited to the extent that modern engines operate with gas temperatures several hundred degrees Celsius (C) beyond the melting point of the component materials. The accurate prediction of hot-section component temperatures is required to avoid component failure. In gas turbine engines, an under-prediction of metal temperatures of only 13°C can impact the life of the component by 50%. Advances in cooling techniques have contributed most significantly to increased turbine inlet temperatures, and hence engine efficiency. The thermal environment of these components must be accurately designed.
Accurate simulations are paramount, yet the designer is left with the daunting task of choosing an appropriate computational model. Industry relevant simulations typically rely on RANS modeling of the turbulent flows. Here the equations of motion are simplified through the introduction of additional transport variables. This requires additional equations for closure of the so-called turbulence problem. Numerous RANS methods exist, however no universal solution exists due to the fact that they are not physics-based.
A sacrifice in solution accuracy is often necessary when numerous flow structures are present. A key aspect of modern simulations methods is therefore in selection of appropriate model parameters such as the turbulence models. The ideal parameters can vary significantly depending on the major flow features present.
For these reasons, the current research thrust is aimed at providing designers with guidelines in the simulation of engine relevant geometries. This is done through the testing of various, commercially available modeling approaches, and thoroughly comparing results against experimental data. This experimental data is collected from the literature as well as through in-house studies carried out in Embry-Riddle's Gas Turbine Laboratory.
Comparisons are multi-tiered, moving from area averaged to local correlations of Nusselt numbers and pressure drop. In an effort to identify the shortcomings of the tested models, additional data is often recorded, such as unsteady velocities and pressures.
Multiple graduate students have been supported by this project and have published several articles. Flow configurations studied have included pin-fin channels , ribbed channels, impingement and impingement channels. Examples are shown below.
Pin-fin Channel Benchmarking (Graduate Student: Royce Fernandes):
Full Coverage Film Cooling (Graduate Student: Simon Martinez):
Ribbed Channel (Graduate Student: Yash Mehta):
- Learn more about research projects in the Daytona College of Engineering and its Department of Aerospace Engineering.
Research Dates
01/01/2014 to 05/10/2016
Researchers
Categories: Graduate