Int. Symp. on Heat Transfer in Gas Turbine Systems 9*14 August 2009, Antalya, Turkey EXPERIMENTAL STUDY OF HEAT TRANSFER FROM IMPINGING JET WITH UPSTREAM AND DOWNSTREAM CROSSFLOW Daniel Thibault, Matthieu F´ enot, Gildas Lalizel and Eva Dorignac Laboratoire d’ ´ Etudes Thermiques - UMR CNRS 6608 ENSMA - University of Poitiers, BP 40109 - 86961 Chasseneuil Cedex France ( corresponding authors: daniel.thibault@let.ensma.fr, matthieu.fenot@let.ensma.fr gildas.lalizel@let.ensma.fr, eva.dorignac@let.ensma.fr) The flow and heat transfer of impingement jets cooling depends on many parameters such as nozzle- to-wall spacing, Reynolds numbers, distance from the stagnation point or design of the injection.The most commonly used geometries in previous studies are axisymetric (circular hole or pipe) and slot (two-dimensional) nozzles [Gardon and Akfirat 1965, Hoogendoorn 1977, Yokobori and al. 1979, Goldstein and al. 1986 and Narayanan and al. 2004]. In internal vane cooling, cool air pass through an impingement channel perforated with multiple holes and then multiple jets impinge on the internal side of the vane (see Fig.1). In the present study, the geometry is a single jet impinging on a flat plate, in order to represent a situation corresponding to the front side and the backside of a vane. In this way, the experimental setup consists of a main crossflow also feeding an injection hole of diameter D h through a thin plate of thickness t (see Fig.2). A secondary crossflow is fixed between the exit of the nozzle and the impingement wall, to simulate the flow stream evacuation from the leading edge to the trailing edge of the vane. Aerodynamic parameters are the Reynolds numbers Re jacket (characterizing the flow field in the jacket cooling circuit and varying from 20 000 to 60 000), Re inj ( in the injection hole and varying from 5 000 to 23 000) and Re air-gap (in the air-gap and varying from 0 to 1000). Geometrical parameters are the nozzle-to-wall distance H with 2 ≤ H/D h ≤ 10 and the thickness of the injection plate t with 0.8 ≤ t/D h ≤ 1.2. The experimental setup is then representative of an internal vane cooling configuration with the assumption of an impingement on a flat plate (typically at the frontside or the backside of the vane) and where the injection plate has a thickness comparable with the injection hole diameter. trailing zone of interest front side back side edge leading edge Cooling air Cooling air Figure 1: Representation of a vane