A Simple Method for the Prediction of Wall Temperatures in Gas Turbines

Abstract

The cited method predicts wall temperatures generally within an accuracy of f 6 percent. The biggest single factor governing the wall temperature is shown to be the hot gas temperature. Other factors discussed are the effects of changes in inlet temperature, fuel types, the geometry of the film cooling devices and manufacturing tolerances. Empirical formulas are given for the prediction of effective temperatures within the various combustor zones. Some comparisons are made between predictions and measurements of wall temperatures over a range of operating conditions.

Problems Associated With Wall Temperature Measurement and Prediction in Small Combustors

“…The results for unvitiated air indicate a better agreement with the prediction than those for the oxygen replenished gases. If all of the above data are examined it will be found that they are in general agreement with the specified conclusions regarding accuracy of prediction [2] and outlined at the start of this section.…”

“…The technique used is a modified version of that published by Lefebvre and Herbert [1]. Full details may be found in [2]. The conclusions from the latter paper are:…”

The Effect of Fuel Composition on Hot Section Performance of a Gas Turbine Engine

“…12]. Of these, Odgers [12] most closely approaches luminosity factors calculated from the radiation data measured at military rated power (Figure 7). A least squares fit based on Odgers' form shows slightly more dependence on hydrogen content.…”

Design methodology for a lean premixed prevaporized can combustor

“…Early work on the heat transfer processes applied to gas turbine combustion by Lefebvre & H erbert (1960) has led to m any publications providing m ethods of estim ating the liner wall tem perature. Ballal & Lefebvre (1972) and Kretschmer & Odgers (1978) are two of these publications. The heat conducted along the liner wall, K, is considered negligible as it is small in comparison to the heat flux by radiation and conduction (Lefebvre.…”

“…Conventional cooling slots provide protection by m eans of a cool insulating barrier of cool air along the liner inside surface. These slots are considered to be inefficient and highly wasteful of air th a t could otherwise be used for combustion (Kretschmer & Odgers, 1978). More advanced cooling schemes have been developed over th e years to achieve the equal or greater degrees of cooling using less air.…”