Browsing by Author "Westley, R."

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    A bibliography and survey of the vortex tube
    (College of Aeronautics, 1954-03) Westley, R.
    A comprehensive bibliography of vortex tube publications is given together with a brief survey of the development of the vortex tube between 1931 and 1953.
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    An investigation of the noise field from a small jet and methods for its reduction.
    (College of Aeronautics, Cranfield., 1952-01) Westley, R.; Lilley, G. M.
    Sound measurements have been made on the noise from the jet of a one inch diameter convergent nozzle at atmospheric temperature and at speeds above and below choking. The noise level and spectrum have been investigated in both the near and distant fields. The results agree in some measure with the predictions of the Lighthill theory, that the elementary sound radiator is an acoustic quadrupole. The agreement is more marked if attention is confined to the higher frequencies. Simple empirical formulae are derived giving the overall sound intensity and frequency spectrum in terms of the position relative to the jet, the stagnation pressure excess over the atmospheric pressure, and the frequency. The results of tests on various noise reduction devices are discussed. These tests indicate promising lines of investigation. The maximum reduction in total noise level was about 10 db.
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    A note on the application of the vortex tube to ventilated suits
    (College of Aeronautics, 1953-04) Westley, R.
    The vortex tube has no moving parts and its makes it an attractive form of refrigerator when a source of compressed air is available. The drawback is that this device has a low efficiency. The proposed application involves passing compressed air, from a jet engine, through a precooler and a vortex tube to the ventilated suit. Investigations show that the temperature of the air entering the ventilated suit is decreased as engine compression ratio and precooler efficiency are increased. Increase of the aircraft's forward speed will result in decreased cooling until a maxim= Mach number is reached above which the ventilated suit cooling requirement, of 115o F, can no longer be satisfied. The maximum permissible Mach number, for an aircraft flying at sea level under the maximum ambient tropical temperature of 45°C, has been calculated over a range of compression ratios, 3 - 15 and precooler efficiencies, 75 - 100 per cent. These results are plotted in figures 6 and 7. It is found that a practical application requires a precooler efficiency of not less than. 80. per cent.
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    On some aspects of the noise propagation from supersonic aircraft
    (College of Aeronautics, Cranfield, 1953-02) Lilley, G. M.; Westley, R.; Yates, A. H.; Busing, J. R.
    The noise problem associated with an aircraft flying at supersonic speeds is shown to depend primarily on the shock wave pattern formed by the aircraft. The noise intensity received by a ground observer from a supersonic aircraft flying at high as well as low altitudes, is shown to be high although it is of a transient nature. Continues…
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    Optimum design of a vortex tube for achieving large temperature drop ratios
    (College of Aeronautics, Cranfield, 1955-05) Westley, R.
    The vortex tube, invented by G.J. Ranque, is a simple device which separates a flow of compressed gas into a hot and a cold stream by means of a high speed vortex. It may have useful applications as a refrigerator and one of the aims of the present investigation was to widen the field of application by increasing the vortex tube's cooling performance. The tests, described in this report, determined the effect of the hot valve setting, the cold outlet diameter, the inlet nozzle size and the inlet pressure ratios, upon the temperature drop ratio characteristics of a vortex tube. The results show that, by matching the inlet nozzles and cold outlet diameter to the inlet pressure ratio, it is possible to obtain, over a wide pressure range, a temperature drop which is 0.50 of the isentropic temperature drop. The optimum cold outlet area is almost independent of the inlet pressure, whilst the optimum inlet area decreases as the pressure ratio increases.
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    The potential due to a source moving through a compressible fluid and applications to some rotary derivatives of an aerofoil
    (College of Aeronautics, Cranfield., 1952-02) Westley, R.
    The first part of this note concerns the evaluation of the potential at a fixed point in space due to an arbitrarily moving source. Continues …
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    Vortex tube performance data sheets
    (College of Aeronautics, 1957-07) Westley, R.
    Experiments to determine the effect of various operating and design parameters on the performance of a vortex tube are described in College of Aeronautics Note No. 30. The present note gives additional performance data on this tube and should be used as a supplement to Note No.30. These data sheets are intended as an aid to the estimation of the performance of vortex tubes and to the design of vortex tubes with given characteristics. In particular, the present note provides the optimum values of the vortex tube parameters which give maximum temperature drops. Figures 12-53 give temperature drop and cold mass flow ratio characteristics, figures 54-61 give the cold mass flow ratios at maximum temperature drop whilst figures 62-65 give the optimum inlet and cold outlet sizes for maximum temperature drop.