Session: 05-16 Instrumentation IV: AI-based Improvements

Paper Number: 129207

129207 - Numerical Assessment of an Aerodynamic Probe to Enable Short Focal Length Laser Diagnostics in High Temperature Supersonic Flows Based on Flow Disturbance 

In high-enthalpy supersonic flows, nonintrusive optical diagnostics are becoming desirable as they avoid the thermomechanical loads and shock-induced disturbances of intrusive sensors, but the limited optical access and long focal lengths imposed by large scale test sections require innovative concepts to allow high resolution flow measurements. This manuscript evaluates the use of an aerodynamic probe body with integrated optics to perform short focal length laser diagnostics within high-temperature, high-supersonic flows (reaching total temperatures of 1700K at Mach 6). The flow disturbance induced by the probe is studied using 3D Steady Reynolds-Averaged Navier-Stokes (RANS) simulations at free stream conditions varying from Mach 5 to Mach 6. The location and shape of the bow-shock formed in the tip of the probe is extracted, and the minimum standoff distance for measurement of the undisturbed flow-field is determined (approximately 5cm at Mach 6). For ensuring the survivability of the hardware, an open cycle cooling scheme is employed, and the effect of coolant being ejected through the front face on the bow-shock and the laser stand-off distance is also evaluated. The beam path is approximated to characterize its deviation due to variations in flow refractive index, and a sensitivity study is performed to evaluate the variation with free stream flow properties. Trends in the laser standoff distance are extracted and related to the inlet Mach number and coolant blowing ratio.

Outline:

1. Introduction

2. Optical probe

2.1. Geometry

2.2. Cooling strategy

3. Methodology

3.1. Numerical domain

3.2. Boundary conditions and grid sensitivity

3.3. Beam trajectory extraction

4. Results and discussion

4.1. Flow disturbance induced by the bow-shock

4.2. Flow disturbance induced by coolant ejection

4.3. Beam path reconstruction

4.4. Sensitivity to free stream conditions

5. Conclusion

 

Presenting Author: Ignacio Lasala Purdue University

Presenting Author Biography: Ignacio Lasala is a Graduate Research Assistant at the Purdue Experimental Turbine Aerothermal Laboratory (PETAL), at Purdue University. His academic journey began in 2019, when he started his undergraduate studies in Aerospace Engineering at the Polytechnic University of Valencia. In the final year of his undergraduate program, he moved to Purdue as part of an exchange scholarship, and started working with the PETAL team. Following the completion of his undergraduate degree in 2023, he decided to pursue a Master's degree in Aerospace Propulsion and become a Graduate Research Assistant at PETAL. Now, his research is primarily focused on innovative methodologies for the application of measurement techniques in high-speed flows.

Authors:

Ignacio Lasala Purdue University
Aubrey Mckelvy Purdue University
James Braun Purdue University
Guillermo Paniagua School of Mechanical Engineering, Purdue University
Etienne Choquet MBDA
Thierry André MBDA
Francois Falempin MBDA