CREATE: Advanced CFD for HPC Performance Improvement

Abstract

The present paper provides an overview of technological evolutions aimed at improving the aerodynamic performance of Snecma’s High Pressure Compressors. Several concepts were investigated under its CREATE compressor research program, involving an extensive simulation effort. An overview of the computational approaches involved in the evaluation and selection of innovative and most promising concepts will be given in the paper. The main topics dealt with are: 1) Aeromechanical optimization of airfoils and flow path: In recent years, great efforts have been made to improve the aerodynamic design of airfoils. Among them, optimization methods have been progressively implemented in the design process with an increased complexity logic. The latest methods used at Snecma involve multi-objective, multi-parameters aeromechanical optimization including mean camber line, stacking axis, flow path contouring and more. This work is illustrated by two practical examples. 2) Vortex generators: In order to control the flow, vortex generators can be forecasted as a promising step forward. The goal is to create exogenous vorticity that will counter-balance the endogenous vorticity. Thus they appear as a tool to reduce losses and improve stability in highly loaded turbomachinery devices such as modern high pressure compressors. This section of the paper will give an overview of the dedicated numerical simulations completed. 3) Clocking: Numerous studies are related to the benefit drawn from turbine clocking on turbomachinery performance. However, fewer examples of successful compressor clocking exist. The recent capability of computational fluid dynamics tools to reduce the computational effort necessary to investigate such an issue (by the use of harmonic balance methodology) gives the opportunity for a renewed evaluation. 4) Optimization of shroud leakage flow with main flow: A strong interaction exists with the secondary flows originated in the inner flow path cavities. Coupled main flow path and cavities aerodynamic simulations were conducted to improve the relevance of the computations and understand the mechanisms involved. 5) Tandem bladings and splitters in axial rotors: The last aspect of the study was focused on dual blading concepts. After a brief review of the literature, some simulations were carried out to explore the relevance of such concepts from the viewpoint of modern high pressure compressors performance improvement.

Helicopter drag reduction by vortex generators

“…Basically conventional zero-thickness vane-type VGs with device height on the order of the local boundary-layer thickness were considered. A dedicated grid generator for VGs was initially developped in the framework of the reduction of secondary flows in high-pressure compressors [5,20]. This grid generator was designed to discretise a VG configuration within the overset grid method [3].…”

Improving work stability margin by determining the optimal and critical parameters of the axial compressor stages

“…Поскольку как срыв, так и помпаж могут ока-зывать катастрофическое воздействие на рабочие характеристики ком-прессора, они вызывают особый интерес в течение многих лет и нахо-дят отражение в литературе [10].…”

Synthetic Separation Control Using Vortex Generator and Slot Jet in a High Load Compressor Cascade

“…The first type is actuator, such as jets (Hecklau et al 2011), plasma actuation (Akcayoz et al 2015), and suction (Guo et al 2013), et al Actuators always need external input devices and additional energy consumption. The second type is geometric shape, such as end-wall contouring (Varpe et al 2015), end-wall fences (Govardhan et al 2012), vortex generator (Pesteil et al 2010;Hergt et al 2006Hergt et al , 2013Wu et al 2016), slot jet (Wu et al 2013(Wu et al , 2014Hu et al 2016Hu et al , 2017, et al Geometric shape usually operates by some geometric design which induces some special flow behaviors and improve the flow field. The geometric shape applications usually need no additional input devices.…”