Experimental Studies and Analysis to Investigate the Characteristics of Real Gas Air Flows in Regions of Shock Wave Boundary Layer Interaction Over a Blunted Double Cone Configuration

摘要

A research program is being conducted to investigate the characteristics and modeling of real gas phenomena in hypervelocity flow at re-entry velocities. These high enthalpy flows will be investigated with surface measurement techniques and non-intrusive methods to evaluate the modeling of flow chemistry. Measurements will be made within regions of fully laminar flow and regions of shock wave/boundary layer interaction over blunt wedge and cone models and then on blunt double wedge and double cone configurations. The experimental studies are being conducted in the LENS XX tunnel for total enthalpies from 5 MJ/kg to 22 MJ/kg (3 to 6.5 km/s) for a range of Reynolds numbers. Freestream conditions have been selected based on CFD computations to excite specific shock layer and boundary layer chemistry and to ensure boundary layer transition does not occur in the reattachment region or in the separated shear layer prior to reattachment of shock interaction regions. The models are instrumented with high frequency thin film heat transfer and piezoelectric pressure gages to detect any occurrence of transition in the interacting flows as well as to map the aerothermal characteristics of the laminar shock interaction regions. Non-intrusive measurements of the flow chemistry as well as high speed Schlieren and interferometric measurements of the density variations are being obtained first on simple configurations in attached flows and then on more complex shapes with embedded regions of shock-induced separated flows.