Efficient Kinetic/Continuum Simulations of Hypervelocity Gas Flows in Nonequilibrium Dissociation and Ionization for Earth Atmospheres

Award Information
Agency: Department of Defense
Branch: Air Force
Contract: FA9550-09-C-0055
Agency Tracking Number: F08A-019-0067
Amount: $99,976.00
Phase: Phase I
Program: STTR
Awards Year: 2009
Solicitation Year: 2008
Solicitation Topic Code: AF08-T019
Solicitation Number: 2008.A
Small Business Information
CASCADE TECHNOLOGIES, INC.
1330 Charleston Road, Mountain View, CA, 94043
DUNS: 179576715
HUBZone Owned: N
Woman Owned: N
Socially and Economically Disadvantaged: N
Principal Investigator
 Shoreh Hajiloo
 General Manager
 (650) 691-6967
 hajiloo@turbulentflow.com
Business Contact
 Parviz Moin
Title: President
Phone: (650) 224-4882
Email: moin@turbulentflow.com
Research Institution
 STANFORD UNIV.
 Mark Cappelli
 Building 520
Mechanical Engineering Dept.
Stanford, CA, 94305
 (650) 725-2020
 Nonprofit college or university
Abstract
In this project, we propose an original method to simulate dissociated and ionized hypersonic air flows from continuum to rarefied regimes for a wide range of scales inherent in Air Force applications. We will introduce the most consistent physical model currently available in kinetic theory. The applicability range of fluid dynamical descriptions used for continuum flows can be extended to the transition regime by taking a finite sequence of moments of the Boltzmann equation together with a closure assumption. The resulting Boltzmann moment systems, solved by CFD methods, are computationally more efficient than statistical methods such as DSMC in the continuum and transition regimes. Therefore, we propose to develop a numerical scheme by blending the Boltzmann moment systems with Levermore closure and the DSMC technique, as opposed to traditional schemes based on the Navier-Stokes equations and DSMC. The coupling will be based on the concept of physics hybridization currently used to couple two vastly different representations of turbulent flows. In Phase I of this project, we will focus on the extension of the Boltzmann moment systems with Levermore closure to dissociating and ionizing hypersonic flows and the development of the computational strategy for the kinetic/continuum algorithm.

* information listed above is at the time of submission.

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