The application of optical imaging techniques to hypersonic facilities is discussed and examples of experimental measurements are provided. Traditional Schlieren and shadowgraph techniques still remain as inexpensive and easy to use flow visualisation techniques. With the advent of faster cameras, these methods are becoming increasingly important for time-resolved high-speed imaging. Interferometry’s quantitative nature is regularly used to obtain density information about hypersonic flows. Recent developments have seen an extension of the types of flows that can be imaged and the measurement of other flow parameters such as ionisation level. Planar laser induced fluorescence has been used to visualise complex flows and to measure such quantities as temperature and velocity. Future directions for optical imaging are discussed.

This paper presents investigations of low-Reynolds-number flows past an SD7003 aerofoil at Re = 60k, where transition takes place across a laminar separation bubble (LSB). Results of experimental measurements and numerical calculations are analysed and discussed. In particular, reasonably good results were obtained using two different numerical approaches: Large-eddy simulation (LES) that demonstrated vortical structures at different transition stages, and where the transition occurred naturally; unsteady Reynolds-averaged Navier-Stokes (URANS) simulations for several turbulence models based on the ω-length-scale equation, coupled to a linear stability solver to predict the transition position.

When the stagnation temperature of a perfect gas increases, the specific heats and their ratio do not remain constant and start to vary with the temperature. The gas remains perfect; its state equations remain valid, so it can be named as calorifically imperfect gas. The aim of this research is to develop the necessary thermodynamic and geometrical equations and to study the supersonic flow at high temperature, lower than the dissociation threshold. The results are found by the resolution of nonlinear algebraic equations and integration of complex analytical functions where the exact calculation is impossible. The dichotomy method is used to solve the nonlinear equations and Simpson’s algorithm for the numerical integration applied. A condensation of the nodes is used. The functions to be integrated have a high gradient at the extremity of the interval of integration. The comparison is made with the calorifically perfect gas to determine the error. The application is made for air in a supersonic nozzle.

Complex weather conditions, especially windshear and icing encounter, have severe effects on aircraft flight safety. The effect of low-altitude windshear and ice accretion on aircraft performance and control has been studied in this paper. With the employment of a windshear model and nonlinear inverse dynamics (NID) method, a low-altitude windshear penetration flight control law is designed. The effect of ice accretion was modeled on the stability and control of an aircraft. Several icing parameters are imported to the small disturbance flight dynamics model to calculate the change of performance, stability and control derivatives between clean and iced aircraft. These derivatives were used to calculate the elevator, the aileron and the rudder step responses to investigate the icing effect.

The simulation results indicate that the NID control logic works effectively in the trajectory control of the aircraft during the penetration of windshear. The method used to study the effect of ice accretion on aircraft is valid and it can provide data for real-time calculation for icing encounter.

The starting process in a supersonic nozzle is numerically simulated. The Navier Stokes equations, in axisymmetric form, are solved using a higher order spatial and temporal accurate scheme. Good comparisons between experimental and numerical values of various flow parameters form the basis of further analysis. The insight of the starting process in the nozzle, namely, the movement of primary and secondary shocks and contact discontinuity, has been obtained through analysis of various flow parameters. It has been observed that the inviscid phenomenon is more predominant in the flow development process. Parametric studies have been carried out to determine the effect of nozzle divergence angle on the starting process.