Assimilation of wall-pressure measurements in DNS of Mach 6 flow over a cone-flare geometry

We perform ensemble-variational assimilation of wall-pressure measurements in direct numerical simulations of Mach 6 flow over a cone-flare. The experimental data are the pressure spectra and intensities at seven wall-mounted PCB sensors, distributed upstream, within, and downstream of the separation region that is established due to the corner shock. The assimilated flow captures the typical intense rope-like structures within the upstream attached boundary layer. A localized amplification of disturbances below the separation shock is predicted, which is not seen in the measurements due to the placement of the sensors. Additionally, the simulations show that the dynamics downstream of separation are the most difficult to predict, due to uncertainty caused in part by the low-frequency unsteady dynamics of the corner shock. This unsteadiness modulates the boundary-layer thickness and modifies the disturbance field.



Funding: Air Force Office of Scientific Research (FA9550-21-1-0345)