Shock tunnel measurements of surface pressures in shock induced separated flow field using MEMS sensor array

Sriram, R and Ram, S N and Hegde, GM and Nayak, MM and Jagadeesh, G (2015) Shock tunnel measurements of surface pressures in shock induced separated flow field using MEMS sensor array. In: MEASUREMENT SCIENCE and TECHNOLOGY, 26 (9).

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Abstract

Characterized not just by high Mach numbers, but also high flow total enthalpies-often accompanied by dissociation and ionization of flowing gas itself-the experimental simulation of hypersonic flows requires impulse facilities like shock tunnels. However, shock tunnel simulation imposes challenges and restrictions on the flow diagnostics, not just because of the possible extreme flow conditions, but also the short run times-typically around 1 ms. The development, calibration and application of fast response MEMS sensors for surface pressure measurements in IISc hypersonic shock tunnel HST-2, with a typical test time of 600 mu s, for the complex flow field of strong (impinging) shock boundary layer interaction with separation close to the leading edge, is delineated in this paper. For Mach numbers 5.96 (total enthalpy 1.3 MJ kg(-1)) and 8.67 (total enthalpy 1.6 MJ kg(-1)), surface pressures ranging from around 200 Pa to 50 000 Pa, in various regions of the flow field, are measured using the MEMS sensors. The measurements are found to compare well with the measurements using commercial sensors. It was possible to resolve important regions of the flow field involving significant spatial gradients of pressure, with a resolution of 5 data points within 12 mm in each MEMS array, which cannot be achieved with the other commercial sensors. In particular, MEMS sensors enabled the measurement of separation pressure (at Mach 8.67) near the leading edge and the sharply varying pressure in the reattachment zone.

Item Type:	Journal Article
Publication:	MEASUREMENT SCIENCE and TECHNOLOGY
Publisher:	IOP PUBLISHING LTD
Additional Information:	Copy right for this article belongs to the IOP PUBLISHING LTD, TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
Keywords:	MEMS pressure sensors; hypersonic flow; shockwave-boundary layer interaction (SBLI); shock tunnels
Department/Centre:	Division of Mechanical Sciences > Aerospace Engineering(Formerly Aeronautical Engineering) Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	10 Dec 2015 06:11
Last Modified:	10 Dec 2015 06:11
URI:	http://eprints.iisc.ac.in/id/eprint/52891

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