TY - GEN
T1 - Gas turbine model scaling
AU - Davies, Mark R.D.
AU - Wallace, John D.
N1 - Publisher Copyright:
Copyright © 1995 by ASME All Rights Reserved.
PY - 1995
Y1 - 1995
N2 - A dimensional analysis, of both the equations governing boundary-layer flow with heat transfer and of the steady and unsteady boundary conditions, demonstrates that twelve non-geometric, dimensionless parameters are required for the complete similarity of a three-dimensional, compressible, viscous flow with a freestream pressure gradient. The analysis shows that non-dimensional groups describing the machine can be reduced to a function of metal angles and twelve fundamentally derived, dimensionless scaling parameters. The equation describing the rate of local entropy generation caused by fluid friction and heat transfer is also non-dimensionalised. This leads to an estimate of the relative magnitude of entropy generation due to fluid friction and heat transfer. A comparison of the principle operating parameters for a number of existing gas turbine test facilities, designed to model the aerodynamic and heat transfer conditions in real engines, suggests that full modelling of engine boundary-layer phenomena has not been achieved. A semi-empirical, boundary-layer analysis suggests that measured velocity boundary-layer profiles from adiabatic test facilities differ significantly with those from a gas turbine operating at engine gas to wall temperature ratios. Similarly, the analysis established the shape of the velocity boundary-layer to be dependent upon the specific-heat ratio.
AB - A dimensional analysis, of both the equations governing boundary-layer flow with heat transfer and of the steady and unsteady boundary conditions, demonstrates that twelve non-geometric, dimensionless parameters are required for the complete similarity of a three-dimensional, compressible, viscous flow with a freestream pressure gradient. The analysis shows that non-dimensional groups describing the machine can be reduced to a function of metal angles and twelve fundamentally derived, dimensionless scaling parameters. The equation describing the rate of local entropy generation caused by fluid friction and heat transfer is also non-dimensionalised. This leads to an estimate of the relative magnitude of entropy generation due to fluid friction and heat transfer. A comparison of the principle operating parameters for a number of existing gas turbine test facilities, designed to model the aerodynamic and heat transfer conditions in real engines, suggests that full modelling of engine boundary-layer phenomena has not been achieved. A semi-empirical, boundary-layer analysis suggests that measured velocity boundary-layer profiles from adiabatic test facilities differ significantly with those from a gas turbine operating at engine gas to wall temperature ratios. Similarly, the analysis established the shape of the velocity boundary-layer to be dependent upon the specific-heat ratio.
UR - http://www.scopus.com/inward/record.url?scp=84976908438&partnerID=8YFLogxK
U2 - 10.1115/95-GT-205
DO - 10.1115/95-GT-205
M3 - Conference contribution
AN - SCOPUS:84976908438
T3 - Proceedings of the ASME Turbo Expo
BT - Heat Transfer; Electric Power; Industrial and Cogeneration
PB - American Society of Mechanical Engineers (ASME)
T2 - ASME 1995 International Gas Turbine and Aeroengine Congress and Exposition, GT 1995
Y2 - 5 June 1995 through 8 June 1995
ER -