Quasi-one-dimensional Scramjet Combustor Flow Solver Using the Numerical Propulsion System Simulation

Abstract

The flow field inside a scramjet engine combustor involves complex phenomena such as fuel-air mixing, combustion chemistry, and flow separation. In order to determine the properties of the flow along the length of the combustor, mass, momentum and energy balance equations are solved simultaneously using a numerical method. While a full three dimensional computational simulation gives detailed results with high order of accuracy, it demands a great amount of time and computational resource. A low order analysis produces a fast overall picture of the combustor operation which in turn provides valuable information suitable for the preliminary design process. This research work aims to describe the analysis process of the scramjet combustor in which a quasi-onedimensional, multi-species, reacting real gas model of the flow is developed to address the limitations in previous researches. The Numerical Propulsion System Simulation (NPSS), into which the NASA Chemical Equilibrium with Applications (CEA) code is integrated, is utilized as the platform to perform the analysis. The analytical model is validated by comparison with experimental data from previous researches. The results obtained by this method are expected to shed some light on the advantages of using detailed chemistry with lower order analysis to calculate scramjet engine performance. v Table of Contents Acknowledgements .

A Multifidelity Simulation Method for Internal and External Flow of a Hypersonic Airbreathing Propulsion System

“…Although three-dimensional simulations provide more accurate details about the physical flows inside the propulsion system, such simulations are time-consuming. Thus, in order to reduce the simulation time and acquire preliminary results for hypersonic cruise vehicles and propulsion systems in the design process, the quasi-one-dimensional method [6][7][8] and the multifidelity simulation method [9] are used. The multifidelity simulation method is characterized by external flow field simulated by a CFD code and an internal flow field, which is solved by a quasi-onedimensional model.…”

“…However, it is difficult to address thermal choke using this method when the Mach number of the flow is unity. To solve the ODE, the core flow area must be prescribed [6]. The other method used to calculate the flow properties is the quasi-one-dimensional unsteady method proposed by Bussing [12], which was developed based on computational fluid dynamic equations and uses the time-marching method to solve the governing equations.…”

“…Their work demonstrates the importance of multifidelity and componentintegrated analysis. Owing to the lack of flame blowout prediction capabilities developed by Vijayakumar et al [18] and Vu and Wilson [6], Connolly et al [19] implemented a generalized DMSJ combustors model in NPSS that can identified four operation modes, including unstart, ramjet, scramjet and blowout of the combustor. Based on NPSS, they built a turbine-based combined cycle, which can operate from takeoff to above Mach 5, successfully simulating mode transition from turbomachinery to DMSJ operation.…”