Evaluation of Pin Fin Cooling Geometries for Turbine Blade Trailing Edge
Kapil Panchala, Pritish Paridab and Srinath Ekkadc
Mechanical Engineering Department, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA.
akpanchal@vt.edu
bpparid1@vt.edu
csekkad@vt.edu
ABSTRACT
Theoretical efficiency of gas turbine cycle depends significantly on the turbine inlet temperatures (TIT) resulting in higher TIT in recent years. Although, the TIT can be higher than 1500K, the blade surface temperature has to be maintained around 1250K due to limitations imposed by allowable maximum material temperature. This requires efficient internal and external cooling of the blades, especially for the initial stages of HP Turbine. Due to the space limitations in the area near the blade trailing edge, pin-fin cooling is the most commonly employed way for internal cooling in this region. The net heat transferred from the blade to air depends on the shape, size, number and spatial arrangement of the pins. Three different pin-fin cooling geometric arrangements in combination with a cutback region with shaped blocks have been studied and compared for the heat transfer and pressure drop performance in the present study through numerical simulation. 3D CFD calculations have been carried out at various Reynolds numbers using commercially available ANSYS-CFXTM code. The deciding parameters for selecting one geometric arrangement over the other have been discussed in detail in terms of both the heat transfer coefficient and pressure drop characteristics.
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