OCR Text |
Show Paper No. 29 COMBUSTOR MODELLING - A MATURING STATE OF THE ART A. Turan, A.U. Chatwani, P.J. Loftus and D.B. Stickler Avco Research Laboratory Textron 2385 Revere Beach Parkway Everett, MA 02149 1.0 INTRODUCTION Practical combustor flows are invariably three-dimensional, turbulent, unsteady, recirculating and reacting. Thus, it is not surprising that earlier attempts in combustor modelling, motivated primarily by the need to produce specific correlations between two or more operating parameters,-4re of limited value as general design tools. The difficulty of developing representative models stems from two related origins; mathematical and physical. The former is due to the fact that various combustor transport processes are numerous, simultaneous and non-linear and the adopted solution procedures consequently stretch the capabilities of the present day computers to the limit. The physical sources of difficulty arise as a result of the complexity of the laws governing turbulent transport and the chemical kinetics of laminar and turbulent gases. Complicating the issue further are phenomena relating to the formation and disappearance of condensed phase particles and thermal radiation through absorbing and scattering media. By virtue of the above interrelated physicochemical phenomena encountered in typical combustors, a representative model must recognize the need to consider some, if not all, of the following areas: i) computational fluid dynamics, ii) turbulence and its interactions, 1 |