Research

Effective Cooling of Gas Turbine (Jet Engine) Elements (CO2 Reduction, Complicated Turbulent Heat Transfer)
Gas turbines are utilized as aircraft jet engines and electric generators, and the performance improvement results in the higher turbine inlet temperature (above 1600deg C). In order to safely operate the high performance gas turbines, the effective cooling of the elements exposed to the high temperature is essential. For example, gas-turbine rotor blade is cooled by using an internal winding flow passage in which the turbulent flow is affected by the external forces like the Colioris force and the buoyancy force in the centrifugal acceleration field. In addition, the sharp 180deg turn and the turbulence promoters (ribs) attached to the inner surface of the flow passage cause the flow separation and reattachment. These effects make the turbulent heat transfer in the rotor blade very complicated. Recently, film cooling at airfoil trailing edge [7]-[9] and pulsating cooling flow effects on it are investigated.[10][11][12]

Heat transfer enhancement on dimpled surface (Large Eddy Simulation)[5].

Heat transfer enhancement on dimpled surface (experimental result using transient technique)[6].

Film cooling of dimpled cutback surface at airfoil trailing edge (experimental result using transient technique)[7][8][9]

Flow velocity vectors in sharp turn measured by using Particle Image Velocimetry.

References

[1] Murata, A. and Mochizuki, S., Effect of Rib Orientation and Channel Rotation on Turbulent Heat Transfer in a Two-Pass Square Channel with Sharp 180-Deg Turns Investigated by Using Large Eddy Simulation, Int. J. Heat Mass Transf., Vol.47(2004), pp.2599-2618.

[2] Murata, A. and Mochizuki, S., Effects of centrifugal buoyancy and Reynolds number on turbulent heat transfer in a two-pass angled-rib-roughened channel with sharp 180-deg turns investigated by using large eddy simulation, Int. J. of Rotating Machinery, Vol.2008 (2008), Article ID 764720, 14 pages.

[3] Murata, A. and Mochizuki, S., Effect of Cross-Sectional Aspect Ratio on Turbulent Heat Transfer in an Orthogonally Rotating Rectangular Duct with Angled Rib Turbulators, Int. J. Heat Mass Transf., Vol.46(2003), pp.3119-3133.

[4] Murata, A. and Mochizuki, S., Large Eddy Simulation of Turbulent Heat Transfer in a Rotating Two-Pass Smooth Square Channel with Sharp 180-Deg Turns, Int. J. Heat Mass Transf., Vol.47(2004), pp.683-698.

[5] Murata, A., Mochizuki, S., Nakamata, C., and Okita, Y., Int. J. of Transport Phenomena., Vol.10, No.4(2008), pp.323-336.

[6] Nishida, S., Murata, A., Saito, H., and Iwamoto, K., Measurement of Heat and Fluid Flow on Surface with Teardrop-Shaped Dimples, CD-ROM Proc. of Asian Congress on Gas Turbines 2009, Aug. 24-26, 2009, Tokyo, Japan, ACGT 2009-TS41, pp.1-4.

[7]Murata, A. Nishida, S., Saito, H., Iwamoto, K., Okita, Y., and Nakamata, C., Effects of surface geometry on film cooling performance at airfoil trailing edge, Trans. ASME, J. of Turbomacihinery, 134(5), 051033 (May 31, 2012) (8 pages).

[8]Murata, A., Mori, E., and Iwamoto, K.，Effects of Surface Geometry and Blowing Ratio on Film Cooling Performance at Airfoil Trailing Edge Investigated by Using Large Eddy Simulation，Proc. of 15th Int. Heat Transfer Conf.(IHTC-15), August 10-15, 2014, Kyoto, Japan, IHTC15-8914(15 pages).

[9]Murata, A., Yano, K., Hanai, H., Saito, H., and Iwamoto, K.，Arrangement Effects of Inclined Teardrop-Shaped Dimples on Film Cooling Performance of Dimpled Cutback Surface at Airfoil Trailing Edge，Int. J. Heat Mass Transf., Vol.107(2017), pp.761-770.

[10] Yamamoto, S., Murata, A., Hayakawa, S., and Iwamoto, K., Three-Component PTV Measurements of Pulsating Film-Cooling Flow over Smooth Cutback Surface at Trailing Edge of Gas Turbine Airfoil, Proc. of Asian Congress on Gas Turbines 2018, Aug. 22-24, 2018, Morioka, Iwate, Japan, ACGT2018-TS77(4pages).

[11] Tokutake, T., Murata, A., Nakajima, D., Yamamoto, S., and Iwamoto, K., Large Eddy Simulation of Film Cooling Performance of Smooth Cutback Surface at Airfoil Trailing Edge Improved by Pulsating Cooling Flow, Proc. of Int. Gas Turbine Congress (IGTC) 2019, Nov. 18-21, 2019, Tokyo Japan, Paper No.47, submitted.

[12] Yamamoto, S., Murata, A., Taniguchi, H., Hayakawa, H., and Iwamoto, K., Effects of Cooling Flow Pulsation on Film Cooling Performance over Smooth Cutback Surface at Airfoil Trailing Edge Measured by Transient Technique with Compensation of Three-Dimensional Heat Conduction, Proc. of Int. Gas Turbine Congress (IGTC) 2019, Nov. 18-21, 2019, Tokyo Japan, Paper No.97, submitted.