Effect of spike truncation on the acoustic behavior of annular aerospike nozzles

Karthikeyan, N and Kumar, Ashwin and Verma, SB and Venkatakrishnan, L (2013) Effect of spike truncation on the acoustic behavior of annular aerospike nozzles. AIAA Journal, 51 (9). pp. 2168-2182. ISSN 0001-1452

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    Abstract

    The work toward reusable single-stage-to-orbit launch-vehicle concepts has initiated several research activities toward a suitable nozzle design, which (unlike bell nozzles) is expected to perform optimally over the entire flight regime. Of these concepts, the annular aerospike nozzle and its variants, linear and truncated, are among the most promising. Given the concern over the intensity of acoustic loading during takeoff, it is vital to carry out a detailed aeroacoustic characterization of aerospike nozzles with special attention to overexpanded conditions, which are generally encountered during liftoff. In this work, an experimental investigation into aeroacoustics of an annular aerospike nozzle of design Mach number (Md) of 2.0 has been carried out, and the results are presented. The effect of truncation of the aerospike to 40 and 60% of the spike length on the acoustic field is also studied and compared with the full-length aerospike. Results show that, in the overexpansion regime, truncated conical aerospike nozzles have reduced acoustic (∼4–5 dB) levels until wake closure compared to the full-length aerospike and conventional convergent–divergent nozzle, all operating at identical conditions. This noise reduction is predominantly in the region upstream of the nozzle exit. At the peak radiation angle (∼150 deg from the jet upstream direction), the acoustic levels are almost same for all of the nozzles investigated in the present study.

    Item Type: Journal Article
    Additional Information: Copyright to this article belongs to M/s. American Institute of Aeronautics and Astronautics
    Uncontrolled Keywords: Spike truncation;Annular aerospike nozzles;Jet aeroacoustics research facility;Acoustic Instrumentation
    Subjects: AERONAUTICS > Aeronautics (General)
    Division/Department: Experimental Aerodynamics Division, Other, Experimental Aerodynamics Division, Experimental Aerodynamics Division
    Depositing User: Ms. Alphones Mary
    Date Deposited: 24 Jul 2015 09:51
    Last Modified: 24 Jul 2015 09:51
    URI: http://nal-ir.nal.res.in/id/eprint/12242

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