Studies of 'N' waves and weak shock waves in the 75 x 100 mm NAL shock tube

Lokhandwala, OA (1977) Studies of 'N' waves and weak shock waves in the 75 x 100 mm NAL shock tube. Technical Report. National Aeronautical Laboratory, Bangalore, India.

Full text available as:
[img] PDF
Restricted to Archive staff only

Download (3332Kb)

    Abstract

    In attenpts to understand the effect of turbulence on sonic boon and the thickening of sonic boom shocks in the atmosphere, transient 'N' waves and weak shock waves were generated by modifying the driver chamber of the existing 75 x 100 mm NAL shock tube. For generation of the transient 'N' waves existing driver chamber was re-placed by area varying chamber viz. pyramidal wedge or abruptly varying area chamber. Due to the diaphragm bursting limitations although all the three chambers could generate clean and reasonably good transient 'N' waves, strength13; of the waves could not be reduced to sonic boom. An orifice13; plate of 0.00125 opening area ratio, placed in the driven13; chamber, could reduced the strength of the 'N' wave but distorted the 'N' wave considerably.13; 13; To remove the distortions of the 'N' wave and to reduce13; the shocks strength further down to sonic boom shocks, weak13; shock waves were generated using combination of large area divergence at the diaphragm and an orifice plate in the driven chamber. Shock waves of various strengths were generated and their rise times were measured. Also to study the effects of turbulence on the wave signature, zero mean flow turbulence was generated in a small section of the driven chamber. The signatures shapes before and after the turbulent chamber were studied. It was observed that the turbulent had not noticeably distorted the travelling signatures. It was also observed that with reduced shock strength, rise times of the shocks had increased, but it could not be concluded whether the increased rise times were due to the reduced strength or due to the methods adopted for generation of the shock waves.

    Item Type: Proj.Doc/Technical Report (Technical Report)
    Uncontrolled Keywords: N waves;Shock waves;Orifice plate;Sonic boom;Shock tube
    Subjects: AERONAUTICS > Aerodynamics
    Division/Department: Aerodynamics
    Depositing User: Mr. Ravikumar R
    Date Deposited: 11 Sep 2006
    Last Modified: 24 May 2010 09:50
    URI: http://nal-ir.nal.res.in/id/eprint/2687

    Actions (login required)

    View Item