TY - GEN
T1 - Local measurement of loss using heated thin film sensors
AU - Davies, Mark R.D.
AU - O'Donnell, Francis K.
N1 - Publisher Copyright:
Copyright © 1998 by ASME All Right Reserved.
PY - 1998
Y1 - 1998
N2 - A calibration equation is derived linking the non-dimensional entropy generation rate per unit area with the non-dimensional aerodynamic wall shear stress and free stream pressure gradient. It is proposed that the latter quantities, which can be measured from surface gauges, be used to measure the profile entropy generation rate. It is shown that the equation is accurate for a wide range of well-defined laminar profiles. To measure the dimensional entropy generation rate per unit area requires measurement of the thickness of the boundary layer. A general profile equation is given and used to show the range of accuracy of a further simplification to the calibration. For flows with low free stream pressure gradients, the entropy generation rate is very simply related to the wall shear stress, if both are expressed without units. An array of heated thin film sensors is calibrated for the measurement of wall shear stress, thus demonstrating the feasibility of using them to measure profile entropy generation rate.
AB - A calibration equation is derived linking the non-dimensional entropy generation rate per unit area with the non-dimensional aerodynamic wall shear stress and free stream pressure gradient. It is proposed that the latter quantities, which can be measured from surface gauges, be used to measure the profile entropy generation rate. It is shown that the equation is accurate for a wide range of well-defined laminar profiles. To measure the dimensional entropy generation rate per unit area requires measurement of the thickness of the boundary layer. A general profile equation is given and used to show the range of accuracy of a further simplification to the calibration. For flows with low free stream pressure gradients, the entropy generation rate is very simply related to the wall shear stress, if both are expressed without units. An array of heated thin film sensors is calibrated for the measurement of wall shear stress, thus demonstrating the feasibility of using them to measure profile entropy generation rate.
UR - http://www.scopus.com/inward/record.url?scp=84973168524&partnerID=8YFLogxK
U2 - 10.1115/98-GT-380
DO - 10.1115/98-GT-380
M3 - Conference contribution
AN - SCOPUS:84973168524
T3 - Proceedings of the ASME Turbo Expo
BT - Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education
PB - American Society of Mechanical Engineers (ASME)
T2 - ASME 1998 International Gas Turbine and Aeroengine Congress and Exhibition, GT 1998
Y2 - 2 June 1998 through 5 June 1998
ER -