HYQ1D (Hypersonic Quasi-1-Dimensional): A Numerical Simulation Tool for Hypersonic Internal Flow Characterization

Hypersonic and supersonic aerodynamic wind tunnels are composed of several components, each designed to accelerate the flow from an initial quiescent state to the desired conditions in the test section. Two of the most common methods to achieve very high velocity and enthalpy conditions involve either the use of an initial detonation or a high-pressure reservoir acting on a free-moving piston, both of which enable the operation of the facility. In general, a hypersonic tunnel consists of three main components. The first is the compression stage, which serves to pressurize the flow. The second component is a shock tube, where the high-pressure flow from the compression stage interacts with a low-pressure region, generating a shock wave that travels along the tube. This shock wave compresses and accelerates the gas toward a nozzle. The nozzle is the third fundamental part. The gas, arriving with very high energy in terms of temperature and pressure, is expanded in the nozzle to reach the desired Mach number in the test section, which is located at the nozzle’s exit. To further investigate and catalog this type of facility, a quasi-one-dimensional code was developed, with a strong emphasis on the modeling of the free-driven piston and thermochemical effects. The wind tunnel mainly used to design and test the code was the hypersonic wind tunnel at Queensland University.