Unsteady heat transfer on turbine blades

1990 ◽  
Vol 4 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Tuncer Cebeci ◽  
Robert J. Simoneau ◽  
Max F. Platzer
Keyword(s):  
Heat Transfer ◽  
Turbine Blades ◽  
Unsteady Heat Transfer

Unsteady Heat Transfer Measurements From Transonic Turbine Blades at Engine Representative Conditions in a Transient Facility

2004 ◽  
Author(s):  
William Allan ◽  
Roger Ainsworth ◽  
Steven Thorpe
Keyword(s):  
Heat Transfer ◽  
Turbine Blade ◽  
Guide Vane ◽  
Turbine Blades ◽  
Reynolds Numbers ◽  
Fast Response ◽  
The Novel ◽  
Unsteady Heat Transfer ◽  
Transonic Turbine ◽  
Nozzle Guide

The unsteady heat transfer measurements about a transonic turbine blade at engine representative Mach and Reynolds numbers are presented. High density, fast response thin film gauges are employed at the mid-height streamline. A description of the novel development of gold gauges together with a brief overview of their calibration and signal processing is presented. Detailed time and phase-averaged measurements have been obtained, providing insight into the role of upstream nozzle guide vane wakes and shock features. These heat transfer results compliment recent fast-response aerodynamic results on this and similar transonic profiles, which highlight the dominance of the upstream vane-rotor interaction over convected wake segments, particularly in light of unsteady turbine blade loading. From a heat transfer standpoint however, whilst the periodic shock events contributed to abrupt, localized heat transfer enhancements, the influence of NGV wake segments on the boundary layer could not be discounted when duration of unsteadiness was considered.

scholarly journals Unsteady Heat Transfer Measurements on a Rotating Gas Turbine Blade

1990 ◽  
Author(s):  
M. A. Hilditch ◽  
R. W. Ainsworth
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Turbine Blades ◽  
Digital Signal ◽  
Two Dimensional ◽  
Unsteady Heat Transfer ◽  
Frequency Spectra ◽  
Dimensional Simulation ◽  
Transfer Signal

Heat transfer measurements made on the rotor blade of a full stage model turbine operating at engine representative conditions are presented. The measurement technique of mounting thin film heat transfer gauges on enamel coated turbine blades enables the heat transfer rate to be measured across a frequency range of d.c. to 100kHz. The output is amplified using electronic circuits housed inside the shaft before transmission through a slipring and digital signal processing routines are used to calculate the heat transfer rate. A calibration experiment in which the gauge is pulsed with a laser beam is described in detail. The results are compared with data from a previous two-dimensional simulation of wake-passing flow on the midheight section of the same blade. The mean heat transfer rate recorded in the two experiments shows reasonable agreement. Fluctuations in the unsteady heat transfer signal at NGV passing frequency are seen at the same locations in data from both experiments, however the magnitude of the fluctuations seen on the rotor are much smaller than those recorded in the two-dimensional simulation. Frequency spectra and correlation analysis of heat transfer traces recorded on the rotor are also presented.

scholarly journals Predicting unsteady heat transfer effect of vehicle thermal management system using steady velocity equivalent method

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110259
Author(s):  
Xiao Guoquan ◽  
Wang Huaming ◽  
Chen Lin ◽  
Hong Xiaobin
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
Management System ◽  
Exhaust System ◽  
Transfer Effect ◽  
Unsteady Heat Transfer ◽  
Thermal Management System ◽  
Comparison Results ◽  
Equivalent Method ◽  
Steady Velocity

In the process of vehicle development, the unsteady simulation of thermal management system is very important. A 3D-CFD calculation model of vehicle thermal management is established, and simulations were undertaken for uphill with full loads operations condition. The steady results show that the surface heat transfer coefficient increases to the quadratic parabolic relationship. The unsteady results show that the pulsating temperatures of exhaust and external airflow are higher than about 50°C and lower than 10°C, respectively, and the heat dissipating capacities are higher than about 11%. Accordingly, the conversion equivalent exhaust velocity increased by 1.67%, and the temperature distribution trend is basically the same as unsteady results. The comparison results show that the difference in the under-hood should be not noted, and that the predicted exhaust system surface temperatures using steady velocity equivalent method are low less 10°C than the unsteady results. These results show the steady velocity equivalent method can be used to predict the unsteady heat transfer effect of vehicle thermal management system, and the results obtained by this method are basically consistent with the unsteady results. It will greatly save computing resources and shorten the cycle in the early development of the vehicle thermal management system.

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