Continuing Validation of Computational Fluid Dynamics for Supersonic Retropropulsion

Analysis of Dynamic Data from Supersonic Retropropulsion Experiments in NASA Langley's Unitary Plan Wind Tunnel

“…This is in agreement with the observation noted in Ref. 13, that the quad-nozzle run 307 exhibits similar periodic behavior to the singlenozzle case.…”

“…13. Further computational analysis of Run 165 describes the unsteadiness as a periodic oscillation of the triple point shown in Fig.…”

Estimation of Uncertainties for a Supersonic Retro-Propulsion Model Validation Experiment in a Wind Tunnel

“…Such a comparison is shown in Figure 19 -taken from [3] for the non-blowing baseline configuration at M = 4.6 and angles of attack of 0, 12, and 20°. The agreement is generally very good on both the forebody and aft body of the model, although some of the predictions fall outside of the experimental uncertainty limits in a few locations.…”

“…The agreement is generally very good on both the forebody and aft body of the model, although some of the predictions fall outside of the experimental uncertainty limits in a few locations. Additional comparisons are provided in [3] for both jet-off and jet-on cases, and information about the CFD computations for SRP are given in [3] and [5]. …”

“…SRP has recently become a focus area of the EDL project within NASA's Exploration Technology Development and Demonstration (ETDD) Program, with present studies to investigate not only hardware integration and system performance, but the complex flowfield as well. SRP results in unsteady jet plume/shock interactions, shear layers, embedded pockets of subsonic flow, and large areas of recirculation -all of which can be difficult to predict accurately using computational fluid dynamics (CFD) codes [3]. Therefore, validation of the CFD tools and methodologies is essential for modeling SRP aerodynamics and aerothermodynamics, and thus continuing to mature SRP technologies.…”