A Fast Computational Module for the Calculation of Equilibrium State Variables and Sonic Speeds in Chemically Reacting Air, for Applications in CFD. G.U. Aero Report 9206

Anderson, J. M. (1992) A Fast Computational Module for the Calculation of Equilibrium State Variables and Sonic Speeds in Chemically Reacting Air, for Applications in CFD. G.U. Aero Report 9206. Technical Report. Department of Aerospace Engineering, University of Glasgow.

Abstract

This report presents a fast technique for calculating the equilibrium thermochemical state of air at high temperatures. The method has been developed for applications in computational fluid dynamics. A six species, three reaction air model is considered, with ionisation of the primary species neglected as a concession to reduced computing times. Both curve fits and statistical expressions are considered for the calculation of the species thermodynamic properties in the range 200 K to 15 000 K. Curve fits are selected as the more efficient technique for evaluating these properties at high temperatures. The temperature range is subdivided into three regions and distinct models for the thermochemical behaviour of air are solved in each region to give the concentrations of the six species. The species properties and concentrations are then used to compute the specific properties of the mixture. The equilibrium and frozen speeds of sound are also calculated. A technique for inverting the state equations is then developed to allow the method to be applied to finite difference algorithms for air flow problems. The scheme is validated against curve fit data and Mollier charts for the high temperature properties of equilibrium air.

• Item Type: Research Reports or Papers (Technical Report)
• Status: Published
• Glasgow Author(s) Enlighten ID: Anderson, Dr John
• Authors: Anderson, J. M.
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Publisher: Department of Aerospace Engineering, University of Glasgow
• Copyright Holders: Copyright © 1992 Department of Aerospace Engineering, University of Glasgow
• Publisher Policy: Reproduced with the permission of the Department