Description and Flow Assessment of the Delft Hypersonic Ludwieg Tube

An assessment of the hypersonic Ludwieg tube of Delft University of Technology is given. The facility is described theoretically, and an experimental evaluation is performed to infer the facility performance. Experiments are performed using conventional techniques such as static and total head pressure measurements and Fay-Riddell heat flux evaluations by means of infrared thermography. Furthermore, particle image velocimetry is used to deduce nozzle boundary-layer parameters as well as the freestream velocity field and the static and total temperatures for the Mach 7 nozzle. For the Mach 9 nozzle, stagnation heat flux measurements are performed to obtain the total temperature of the flow. The freestream values were determined experimentally in two different ways and the results showed good agreement. The application of particle image velocimetry allows the freestream flowfield to be directly obtained and gives a direct measure for the flowfield uniformity (0.2%) and repeatability (0.4%). The static and total temperatures calculated from the particle image velocimetry results showed that there is a large mismatch between the theoretical total temperature and measured total temperature, which is attributed to heat losses present in the throat and nozzle.