Experimental studies are carried out to investigate the effects of the geometrical parameters with a drag reducing spike on a hemispherical forebody in a supersonic freestream of M = 2.0 at 0 deg angle of attack. The spike length ( l / D = 0.5 , 1.0, 1.5, 2.0), spike stem diameter ( d / D = 0.06 , 0.12, 0.18), and spike tip shapes are varied, and their influence on the time-averaged and time-resolved flowfield is examined. When l / D increases, a significant reduction in drag c d is achieved at l / D = 1.5 , whereas the variation in d / D has only a minor effect. The intensity of the shock-related unsteadiness is reduced with an increase in d / D from 0.06 to 0.18, whereas changes in l / D have a negligible effect. The effects of spike tip geometry are studied by replacing the sharp spike tip with a hemispherical one having three different base shapes (vertical base, circular base, and elliptical base). A hemispherical spike tip with a vertical base is performing better by reducing c d and flow unsteadiness. The dominant spatiotemporal mode arising due to the shock-related unsteadiness is represented through modal analysis of time-resolved shadowgraph images, and the findings are consistent with the other measurements.


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    Title :

    Parametric Experimental Studies on Supersonic Flow Unsteadiness over a Hemispherical Spiked Body


    Contributors:

    Published in:

    AIAA Journal ; 58 , 8 ; 3446-3463


    Publication date :

    2020-06-03


    Size :

    18 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English




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