Stagnation temperature in a cold hypersonic flow produced by a light free piston compression facility

Widodo, Agung and Buttsworth, David (2013) Stagnation temperature in a cold hypersonic flow produced by a light free piston compression facility. Experiments in Fluids, 54 (4). p. 1486. ISSN 0723-4864


Stagnation temperatures at the nozzle exit of the University of Southern Queensland hypersonic wind tunnel facility have been identified using an aspirating tube device with a 0.075 mm diameter k-type butt-welded thermocouple junction positioned at its inlet. Because of the finite thermal inertia of the thermocouple, a response time correction is introduced, and uncertainties in the response time correction are assessed and minimized by operating the aspirating device over a range of different initial temperatures. Pressure measurements within the barrel of the wind tunnel facility were used to estimate a theoretical upper bound on the flow stagnation temperature by assuming isentropic compression of the test gas. Results demonstrate that for the current operating conditions, the gas which is first delivered into the hypersonic nozzle has a stagnation temperature almost identical to the isentropic compression value of around 560 K, but a cooling effect is registered for the duration of the test flow which is about 200 ms. Thermodynamic simulations based on an unsteady energy balance model with turbulent heat transfer from the test gas within the barrel demonstrate a cooling effect of a similar magnitude to that indicated by the measured temperature variation, suggesting that strong mixing of the test gas occurs within the barrel during flow discharge through the hypersonic nozzle.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: © 2013 Springer-Verlag Berlin Heidelberg. Permanent restricted access to published version due to publisher copyright policy.
Faculty/School / Institute/Centre: Historic - Faculty of Engineering and Surveying - No Department
Date Deposited: 13 Nov 2014 04:07
Last Modified: 23 Mar 2017 03:42
Uncontrolled Keywords: energy balance models; hypersonic wind tunnels; isentropic compression; measured temperatures; thermocouple junctions; thermodynamic simulations; turbulent heat transfer; wind-tunnel facilities
Fields of Research : 09 Engineering > 0915 Interdisciplinary Engineering > 091501 Computational Fluid Dynamics
09 Engineering > 0901 Aerospace Engineering > 090107 Hypersonic Propulsion and Hypersonic Aerodynamics
09 Engineering > 0915 Interdisciplinary Engineering > 091502 Computational Heat Transfer
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970109 Expanding Knowledge in Engineering
Identification Number or DOI: 10.1007/s00348-013-1486-6

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