A transonic wind tunnel was designed, constructed and calibrated in order to provide a valuableudtool for the study of transonic flow phenomena. The wind tunnel makes use of flow propertiesudsurrounding the propagation of a shock wave along a tube in order to create the transonic flow.udAs a result, the wind tunnel is a modified shock tube, with its layout being optimised forudmaximum flow time. The flow times are dependent on the Mach number of the transonic flowudbeing created, with the longest realistic flow time being approximately sixty milliseconds. Theudmajority of the shock tube was built from commercially available steel construction tubing whichudwas then attached to a pressure vessel of similar cross sectional dimension. A test sectionudcontaining windows was constructed and placed in a position along the length of the tube toudmaximise the available test flow time. The position optimisation was calculated based on standardudshock wave theory. The incident shock wave, as well as any resulting flow features, wereudvisualised using schlieren photography. The test piece was designed to be set at angles of attackudof up to ten degrees, both positive and negative. The main purpose of the testing carried out wasudto validate the functioning of the wind tunnel rather than obtaining more data on the test piece.udAn RAE2822 aerofoil was used as the test piece due to the large amount of aerodynamic dataudavailable on it, especially in the transonic flow region, thus making it an excellent tool forudvalidation. In addition, the Fluent computational fluid dynamics package made use of the sameudaerofoil to validate their numerical results when the package was under development. This meantudthat for any numerical result obtained for the RAE2822 aerofoil using the Fluent package, thereudwas a high degree of confidence. This fact provided a great tool for comparing results obtainedudexperimentally in the wind tunnel with results obtained numerically. The short duration testingudtime was found to be adequate for establishing semi-steady state flow at any transonic flow Machudnumber. The bursting of the weak diaphragm at the end of the driven section of the shock tubeudresulted in the upstream propagation of a disturbance with a much lower velocity than would beudseen if the incident shock wave reflected off a solid boundary and thus its arrival at the testudsection was delayed, resulting in a significant increase in testing time.udThe results obtained experimentally compared well to results obtained numerically. Transonicudshock waves that were set up on the test piece had very similar shapes, features and chord-wiseudpositions in both experimental and numerical results, showing that the geometric layout of the testudsection was correct. Furthermore, it was shown that a short duration flow time wind tunnel couldudbe constructed using a shock tube and that accurate results could be obtained through its use.
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