Transonic Axial Compressors Loss Correlations: Part I — Analysis and Update of Loss Models

Abstract

The quest for greener, more efficient aircraft engines is the main driver for the development of innovative compression system designs. Reduced order design tools rely nevertheless on semi-empirical loss models, whose validity range is often not net or in general not verified. The present work aims at defining a set of loss correlations, which could readily be employed in the analysis and design process of modern transonic axial compressors. In part I, the main entropy generation mechanisms are described together with a review of the most commonly employed modelling approaches. Selected loss models are then deeper investigated and updated to increase both their range of validity and the accuracy of their predictions. In Part II, the effectiveness of the investigated models will be tested for one specific low aspect ratio axial compressor stage.

A CFD-Based Throughflow Solver Using Cascade Potential Theory for Axial Compressor Flow Modeling

“…Recent designs of axial compressors blade showed diversified profile shapes, increased solidity due to larger chords and reduced blade aspect ratios compared to the precedent generations. This brings difficulties to estimate the correct loss levels with classical semi-empirical models mostly based on cascade test cases such as the well-known Lieblein correlations [9,18]. This fact has motivated the testing of a more locally driven approach based on local geometry as it will be described in the next section of this paper.…”

“…If the recent better understanding of 3D flow features is admitted, the reduction of this knowledge to reliable reduced order model adaptable to throughflow simulations is not yet systemically observed as noticed by Banjac et al [8]. In addition to this, the legacy models used in the past show limited accuracy for modern designs [9]. This is why models must continuously be developed to improve new generation of throughflow codes suitable for modern compressor design methodologies.…”