4 Rebuilding and Analysis of a SCIROCCO PWT Test on a Large TPS Demonstrator Sara Di Benedetto, Giuseppe C. Rufolo, Marco Marini and Eduardo Trifoni CIRA, Italian Aerospace Research Centre Italy 1. Introduction In September 2007, a Plasma Wind Tunnel (PWT) Test was performed in the CIRA SCIROCCO facility on the FLPP Snecma Propulsion Solide (SPS) Thermal Protection System (TPS) demonstrator (Barreteau et al., 2008). Aim of the test was to verify, in a space qualifying environment, the behaviour of a large assembly constituted by Ceramic Matrix Composite (CMC) shingles, one curved and two flat panels, the same elements which will be part of the next ESA Intermediate Experimental Vehicle (IXV) thermal protection system. The focus of this chapter is the description of the CFD activities carried out in order to realize and support the plasma wind tunnel test, both in the phase of test definition and for the post test analysis. During the pre-test CFD activity the test condition, previously defined by a simplified two dimensional methodology (Rufolo et al., 2008), has been verified by means of three dimensional simulations, and the final PWT test condition has been defined. Then, the post- test CFD rebuilding activity has allowed the analysis of results and the comparison with experimental measurements. In addition, an assessment of the uncertainty level related to the satisfaction of the test requirements, in terms of heat flux and pressure to be realized over the test article, has been provided by analyzing the sources of error linked to both design and testing phases. 2. Test requirements The test article is an assembly of CMC TPS elements: two flat panels located at 45 degrees with respect to the plasma flow and a curved panel which constitutes the model leading edge. The test article configuration and its dimensions are represented in Fig. 1. Each portion of TPS to be tested (in white in figure) is separated by the other ones by a gap (1.5 mm in depth and 3 mm in width), in such a way to form a “T-gap” configuration. The initial test design phase had been carried out in order to answer to the following customer requirements: • cold-wall (T w =300 K), fully catalytic heat flux of 320 kW/m 2 ± 10% at the beginning of the flat panels; • constant wall pressure of 25 mbar a maintained during the test on the two flat panels surface.