This investigation concerns the design, build, and testing of direct-measuring skin friction sensors capable of performing in sustained hypersonic flow and detecting transition. A multistep approach tested the sensors through bench-test and wind-tunnel facilities. The sensors underwent National Institute of Standards and Technology traceable calibrations with well-documented uncertainties. The calibration process characterized static, thermal, pressure, and dynamic responses. Validation testing was conducted in a supersonic tunnel at Mach 4.0. The main investigations were conducted in Arnold Engineering Development Complex Tunnel 9. The skin friction sensor was integrated into a steel 155.6-cm-long (61.27 in.-long), 7 deg half-angle cone model. Flow was nominally maintained at Mach 10 and a stagnation temperature of 1250 K (2250°R). The stagnation pressure and unit Reynolds number were varied over 2.3-43.4 MPa (330-6300 psia) and 1.6-30.3 × 10 6 ∕m (0.5-9.24 × 10 6 ∕ft), respectively. Skin friction was measured over boundary-layer states including early transitional, transitional, and turbulent flows. Wall shear ranged between 0.92 and 340 Pa (0.02 and 7.1 psf), whereas the skin friction coefficients ranged 0.0003-0.0060. The uncertainty of the skin friction sensor remained at 9.2% of the measurement for a 95% confidence level. The experimental measurements demonstrated favorable agreement with independent analyses including numerical predictions and Reynolds analogy methods.

A computer model of a blow-down free-jet hypersonic propulsion test facility exists to validate facility control systems as well as predict problems with facility operation. One weakness in this computer model is the modeling of an air ejector diffuser system. Two examples of facilities that could use this ejector diffuser model are NASA Langley Research Center's 8-ft High Temp. Tunnel (HTT) and the Aero-Propulsion Test Unit (APTU) located at Arnold Engineering Development Center. Modeling an air ejector diffuser system for a hypersonic propulsion test facility includes modeling three coupled systems. These are the ejector system, the primary free-jet nozzle that entrains secondary airflow from the test cell, and the test article. Both of these facilities are capable of testing scramjets/ramjets at high Mach numbers. Compared with computer simulation data, experimental test cell pressure data do not agree due to the current modeling technique used. An improved computer model was derived that incorporates new techniques for modeling the ejector diffuser. This includes real gas effects at the ejector nozzles, flow constriction due to free-jet nozzle and ejector plumes, test article effects, and a correction factor of the normal shock pressure ratio in a supersonic diffuser. A method was developed to account for the drag and thrust terms of the test article by assuming a blockage factor and using a drag coefficient*Area term for both the test article and thrust stand derived from experimental data. An ideal ramjet model was also incorporated to account for the gross thrust of the test article on the system. The new ejector diffuser model developed improved the accuracy and fidelity of the facility model as compared with experimental test data while only negligibly affecting computational speed. Comparisons of the model data with experimental test data showed a close match for test cell pressure (within 1 percent for final test cell pressure). The model accurately simulated both the unstarted and started modes of ejector flow, in which test cell pressure increases with nozzle total pressure once in started mode.

No abstract

No abstract

Sampling of blood in abattoirs is assuming increasing rose bengal, serum agglutination or complement fixation importance in the Queensland brucellosis control pro-testing. gramme. It is planned to test serums from female After the serums had separated from the clots. the breeders sent to slaughter at all the major export abat-RBPT was performed. The test was interpreted on a testing, and the management of Tancred Bros. Bromelton, and Thos Borthwick and Sons, Murarrie, for their cooperation.