Section: Overall Objectives

Overall Objectives

This project aims at studying a particular sort of jet that is often encountered in internal aerodynamic: the jets in crossflow (see Figure 1 -top). The originality of this project stems from the simultaneous and strongly coupled experimental and numerical studies of such jets.

From an experimental point of view, the test facility Maveric (MAquette pour la Validation et l'Expérimentation sur le Refroidissement par Injection Contrôlée) built three years ago at LMA and its metrology is used. An overview of this test rig is presented in Figure 1 -bottom. This test facility is able to produce the kind of flow depicted in Figure 1 -top. The configuration of an isolated jet in a turbulent crossflow will be carefully investigated to produce high quality data (mainly related to the velocity field properties). One-component laser Doppler velocimetry (LDV) as well as particle image velocimetry (PIV) are the two workhorses to be used in order to experimentally characterize the flowfield.

Figure 1. MAVERIC test facility: visualization of a single jet in crossflow (top) and overview of the test rig (bottom).

A close interaction during the course of the project between experiments and simulation will be established. From the simulation point of view, the aim is to be able to perform within two years a direct numerical simulation of an isothermal configuration of an inclined jet in crossflow in turbulence conditions, with a compressible solver that must be still accurate at low Mach number. Considering the challenge that such a task represents, a collaboration has been established with the Bacchus team in order to avoid too many useless redundancies. The Cagire team shares with Bacchus a common framework of development in which both common and team specific tools are being elaborated. From a numerical point of view, the challenge stems from the recourse to hybrid unstructured meshes, which is mandatory for our flow configuration, and implicit time integration, which is induced by the low Mach number of the flow. From the point of view of the interaction between experiments and CFD, the challenge will be mostly related to the capability of ensuring that the flow simulated and the flow experimentally investigated are as identical as possible.