Numerical Modeling of Compressible Flow and Its Control
Abstract
This report describes work carried out on numerical modeling of high Mach number flows and their control. Two main technical areas were addressed: nanosecond-pulse, dielectric barrier discharge flow control actuators, and large-scale unsteadiness in separated shock-wave/boundary-layer interactions. Numerical simulations of experiments in the Ohio State University Mach 5 tunnel on control of a cylinder flow with a plasma actuator revealed the interaction of the disturbance generated by the actuator with the bow shock, and ruled out sidewall interactions as a major influence on the experiments. High-fidelity fluid simulations of nanosecond-pulse discharges demonstrated the importance of rapid relaxation of excited neutrals and recombination of ions in generating the flow disturbance. Comparisons of fluid simulations with particle-in-cell simulations showed good agreement, confirming the appropriateness of the fluid approach. In a supersonic compression ramp flow, a gliding discharge plasma actuator was found to be very effective in reducing the extent of separation and the low-frequency content of the turbulent fluctuations. This low-frequency content was examined in data from wind tunnel experiments, Hypersonic International Flight Research Experimentation flight test 1 (HiFIRE-1), and large-eddy simulations, and was found to agree with a theory developed by Plotkin that represents the separation bubble as a frequency-selective amplifier. This approach to understanding of the physics of separation unsteadiness, combined with effective flow control actuators, shows promise for mitigating fatigue loading on high Mach number aircraft.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2014
- Accession Number
- ADA599340
Entities
People
- Jonathan Poggie
Organizations
- Air Force Research Laboratory