Uncertainty Quantification Applied to Gas Turbine Components

Abstract

The previous chapters analyzed the level of uncertainty in different gas turbine components, how this affects the performance such as life and fuel consumption and the numerical uncertainty introduced by the CFD modelling itself. This chapter will show how Uncertainty Quantification techniques are used nowadays in CFD to study the impact of such manufacturing errors, pointing out, for each component, what has been learned and/or discovered using UQ and which methodology has been used. UQ is mainly considered in gas turbine in order to add an “error bar” to the CFD predictions. However we would like to show that one of the most interesting application of UQ is to understand the impact of variations from a design point of view and to “investigate” the reason of a problem. A very good example is shown by Seshadri et al. [12] where the authors used UQ to find the real reason of disagreement between CFD and experiments on NASA rotor 37 test case. Even if it was speculated for several years that a possible reason was the leakage in front of the rotor, Seshadri was able to quantify the impact of uncertainty due to the leakage.