Combined 3D Flow and Heat Transfer Measurements in a 2-Pass Internal Coolant Passage of Gas Turbne Airfoils

A study of the flow and heat transfer in a stationary model of a two-pass internal coolant passage is presented, which focuses on the flow characteristic effects on the wall heat transfer distribution. Results are given in the upstream fully developed region. Heat transfer measurements were made with a transient technique using thermochromic liquid crystal technique to measure a surface temperature. The technique allows full surface heat transfer coefficient measurements on all the walls. Flow measurements were made with a stereoscopic digital PIV system, which measures all three-velocity components simultaneously. The coolant passage model consists of two square ducts, each having a 20 hydraulic diameter length. The ducts are connected by a sharp 180° bend with a rectangular outer wall. 45° ribs are mounted in a staggered arrangement on the bottom and top walls of both legs. The height of the ribs is equal to 0.1 hydraulic diameters. They are spaced 10 rib heights apart. The flow and heat transfer measurements were obtained at one flow condition with an inlet flow Reynolds number, based on the hydraulic diameter, of 50,000. The paper presents detailed measurement results of the flow characteristics and of the heat transfer distribution in the upstream straight leg of the passage and describes how the main and secondary flows influence the heat transfer distribution in the fully developed regions of the channel.Copyright © 2002 by ASME

[1]  Je-Chin Han,et al.  Local Heat/Mass Transfer and Pressure Drop in a Two-Pass Rib-Roughened Channel for Turbine Airfoil Cooling. , 1987 .

[2]  Je-Chin Han,et al.  Developing heat transfer in rectangular channels with rib turbulators , 1988 .

[3]  PIV investigation of the flow characteristics in 2-leg internal coolant passages of gas turbine airfoils , 2001 .

[4]  C. P. Lee,et al.  Augmented Heat Transfer in Square Channels With Parallel, Crossed, and V-Shaped Angled Ribs , 1991 .

[5]  A Boelcs,et al.  A Novel Digital Image Processing System for the Transient Liquid Crystal Technique applied for Heat Transfer and Film Cooling Measurements , 2001, Annals of the New York Academy of Sciences.

[6]  Je-Chin Han,et al.  LOCAL HEAT TRANSFER DISTRIBUTIONS NEAR A SHARP 180° TURN OF A TWO-PASS SMOOTH SQUARE CHANNEL USING A TRANSIENT LIQUID CRYSTAL IMAGE TECHNIQUE , 1995 .

[7]  Rainer Höcker,et al.  Optimization of Transient Heat Transfer Measurements Using Thermochromic Liquid Crystals Based on an Error Estimation , 1996 .

[8]  Sadanari Mochizuki,et al.  Effects of Rib Arrangements on Pressure Drop and Heat Transfer in a Rib-Roughened Channel With a Sharp 180 deg Turn , 1997 .

[9]  A. Bölcs,et al.  Experimental and Numerical Study of Developed Flow and Heat Transfer in Coolant Channels With 45 and 90 Degree Ribs , 1998 .

[10]  A. Bölcs,et al.  PIV Investigation of the Flow Characteristics in an Internal Coolant Passage With Two Ducts Connected by a Sharp 180° Bend , 1998 .

[11]  S. Parneix,et al.  Prediction of pressure loss and heat transfer in internal cooling passages , 2001, Annals of the New York Academy of Sciences.

[12]  A. Bölcs,et al.  Investigation of turbulent flow by means of the PIV method , 1996 .

[13]  Guido Rau,et al.  Einfluss der Rippenanordnung auf das Strömungsfeld und den Wärmeübergang in einen Kühlkanal mit quadratischem Querschnitt - Thèse de doctorat , 1998 .

[14]  Peter T. Ireland,et al.  Heat Transfer Measurements to a Gas Turbine Cooling Passage With Inclined Ribs , 1996 .

[15]  Jochen Schabacker.  PIV investigation of the flow characteristics in internal coolant passages of gas turbine airfoils with two ducts connected by a sharp 180° bend , 1998 .

[16]  Bernhard Weigand,et al.  A new evaluation method for transient liquid crystal experiments , 2001 .