In a previous paper1 the author and co-workers reported an unexpected numerical behavior in the simulation of dual-mode scramjet combustors. Under conditions of perfect symmetry in geometry, grid and boundary conditions, computational fluid dynamic (CFD) calculations showed an asymmetric response when a shock-train/separated-flow system was present in the flowfield. Other researchers using a co...

A seven-species hypersonic flow solver that independently tracks vibrational energies of diatomic species has been coupled with SPRADIAN for the purposes of developing a spectrally accurate coupled radiation / flowfield solution. Results are presented for the FIRE-II and RAM-C geometries, and compared to experiment results where available. Shortfalls of the method are identified, along with ave...

A class of generalized high order finite compact difference schemes is proposed for shock/vortex, shock/boundary layer interaction problems. The finite compact difference scheme takes the region between two shocks as a compact stencil. The high order WENO fluxes on shock stencils are used as the internal boundary fluxes for the compact scheme. A lemma of the property of smoothness estimators on...

The visual flow field, produced by forward locomotion, contains useful information about many aspects of visually guided behavior. But locomotion itself also contributes to possible distortions by adding head bobbing motions. Here we examine whether vertical head bobbing affects velocity discrimination thresholds and how the system may compensate for the distortions. Vertical head and eye movem...

In this work, we propose a framework whereby flow imaging data is leveraged to extract relevant information from flowfield visualizations. To end, vision transformer (ViT) model developed predict the unsteady pressure distribution over an airfoil under dynamic stall images of flowfield. The network capable identifying features present in and associate them response. Results demonstrate that eff...

A chemical reaction model, suitable for use in the Direct Simulation Monte Carlo (DSMC) method, is developed to simulate hypervelocity collisions of an important reaction in atmospheric-jet interactions O(3P)+HCl(1Σ ) OH(2Π)+Cl(2P). The model utilizes the Quasi-Classical Trajectory (QCT) method with two potential energy surfaces (PES), new benchmark triple A and A surfaces and London-Eyring-Pol...

Although wake vortices are known to decay more rapidly near the ground than away from the ground, the details of the ground interaction are not well understood. Propeller anemometer arrays located under the approach path have been used to study vortex transport and provide some information about the vortex interaction with the ground, such as the generation of secondary vortices via boundary-la...

Depending on the case study examined, different PSPs may be used, each applied using a different method onto the model. For polymer PSP the paint is sprayed on. In contrast, the model may first be anodized or covered with a thin-layer chromatography plate and then dipped in PSP. The objective of the present study is to analyse the characteristics of different PSP substrates at high Mach numbers...

A numerical analysis is carried out to determine the flowfield and starting characteristics of a straight cylindrical supersonic exhaust diffuser of a high-altitude simulation of a high expansion ratio rocket nozzle. The flow field inside the high-altitude facility is analyzed for a conical nozzle of expansion ratio of 25, diffuser inlet-to-nozzle throat area ratio of 28.9, and diffuser length-...