Application of Particle Image Velocimetry to High-Speed Supersonic Flows in a Shock Tunnel
Particle Image Velocimetry (PIV) has become an important tool in modern flowfield diagnostics, in particular for subsonic flows. PIV systems have also been used to measure supersonic flows in supersonic wind tunnels, but only recently it has been shown that PIV can also be a valuable tool for high-speed supersonic flows in a shock tunnel (Haertig et al., 2001). At the ISL shock tunnel a PIV system was installed and tested (Fig. 1). A shock tunnel is a transient wind-tunnel facility with short testing times of a few milliseconds and high supersonic flow velocities in the km/s range. The short flow duration time makes a high information density highly desirable. An application of PIV to such kind of flows is considerably more difficult than to a continuous flows, however, because no online adjustments of the particle seeding and the optics can be done. In this publication, PIV measurement results obtained for flows at Mach numbers of 4.5 and 6 with velocities of up to 1.8 km/s are presented. We measured the freestream flow of nozzles, supersonic wedge flows with an attached shock wave, and the supersonic flow around a sphere with a detached shock wave. To obtain a good spatial resolution a laser pulse separation of less than 0.5 μs is necessary. Solid particles (TiO2 and Al2O3) with a nominal diameter of about 0.3 μm were used for the seeding. The measured particle relaxation across shock waves was found to be consistent with theoretical estimations. Because of the strong particle density gradients in shock waves, the PIV correlation algorithm can contribute to considerable inaccuracies, however. Fig. 1. ISL shock-tunnel facility with PIV system.
Experimental investigation of re-entry aerodynamic phenomena - Development of non-intrusive ?ow diagnostics in a Ludwieg tube
To further improve the design of hypersonic vehicles so that fully reusable systems become a reality, the detailed understanding of the ?ow ?eld that the vehicle generates is of paramount importance. The thesis deals with the aspects of experimental ?ow research which includes also the ?ow facility and the measurement techniques. First a description is given of the investigation and assessment of the Hypersonic Test Facility Delft (HTFD), which is the facility used in the experiments. Thereafter two measurement techniques, particle image velocimetry (PIV) and quantitative infrared thermography (QIRT) are introduced that enable to obtain high quality measurement data of the hypersonic ?ow ?eld generated by the HTFD. In the remainder of the thesis two important ?ow phenomena, shock wave boundary layer interaction and boundary layer transition, have been investigated using PIV and QIRT that are of great importance for re-entry vehicles.
Cultivated Power: Flowers, Culture, and Politics in the Reign of Louis XIV
Ch. 1. Disorderly flowers Floral seduction: death, sex, and flowers Trading on the power of flowers Ch. 2. Refashioning the culture of flowers in early modern France Curiosity and flowers The sweet society of the curious florists Ch. 3. Cultivating the flower The florists' flowers Unlocking the door to the temple of flora Ch. 4. Cultivating the man The theater of the goddess of flowers Nature into art "Jardin d'Hyver," or flowers in print Ch. 5. Cultivating the king Royal precedents Flowers in the garden of Louis XIV Floral mercantilism Flowers and the "Histoire du Roi" Appendices A. Extract of the inventory by ... Sieur Cottereau of flowering plants and bulbs that he offers to furnish for the gardens of the royal households B. Plants included in Jean Donneau de Vise's Histoire de Louis le Grand