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Multiple Helmholtz Resonator Heat Flux Reduction Concept

Award Information

Department of Defense
Air Force
Award ID:
Program Year/Program:
1996 / SBIR
Agency Tracking Number:
Solicitation Year:
Solicitation Topic Code:
Solicitation Number:
Small Business Information
Applied Sciences, Inc.
141 W. Xenia Ave. PO Box 579 Cedarville, OH 45314-
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Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No
Phase 1
Fiscal Year: 1996
Title: Multiple Helmholtz Resonator Heat Flux Reduction Concept
Agency / Branch: DOD / USAF
Contract: N/A
Award Amount: $62,176.00


A new thermal protection concept is described and an investigation to determine its feasibility and quantify its performance is proposed. The concept involves placing an array of small cavities in the nose region of a typical hypersonic interceptor (projectile, missile, or submunition). The cavities act as multiple Helmholtz resonators, and can be made to operate in a very predictable manner to alter the inviscid strain field in the stagnation region. In effect, the resonators simulate a body with a more blunt nose geometry than actually exists. In addition, they provide "thermoacoustic" cooling from the adiabatic expansion/compression mechanism. The design is both simple and inexpensive since there is no hardware or active control device to install. The investigation is primarily experimental however a theoretical component is included to help interpret and explain the experimental results. Global surface temperature measurements will be made with an IR camera. Surface flow patterns and bow shock wave visualizations will be performed. In addition, fluctuating pressure measurements inside the cavity will be made and correlated with the global temperature and shock wave shapes. The concept also has a potential ancillary aero/optic application. Since the resonators can create a nearly planar bow shock, this effect could be useful in minimizing radial density gradients in the nose region thus reducing boresight errors for forward looking sensors.

Principal Investigator:

Dennis Wilson

Business Contact:

Small Business Information at Submission:

Applied Sciences, Inc.
P.O. Box 8134 Hampton, VA 23666

Number of Employees:
Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No