An Enhanced Software Toolkit for OpenNCC to Reduce NOx in Commercial Supersonic Transport Combustors

The innovation proposed is a second-generation Software Toolkit enabling improved predictions of oxides of nitrogen (NOx) in high-fidelity yet computationally-tractable Computational Fluid Dynamics (CFD) analyses of combustor concepts applicable to Commercial Supersonic Transport (CST) designs. Given the technical challenges to meet the more stringent NOx emission limits at the higher CST cruising altitudes and the unique characteristics of the CST thermodynamic cycle, the proposed innovation intends to enhance the capabilities of the first-generation Software Toolkit for NASArsquo;s OpenNCC CFD code. The second-generation Software Toolkit will feature (i) enhanced predictive accuracy of the primary turbulent flame with real fuels (HyChem conventional/alternative fuels) and NOx by relaxing the dilute NOx assumption, (ii) computational efficiency, and (iii) software portability, e.g., to NASArsquo;s OpenNCC. Since CST combustor concepts will operate at higher temperatures and with higher fuel flow rates, a detailed understanding of flame dynamics is required, in particular within the context of parametric or trade studies. Given the competing performance and emission targets to be considered, a large number of design parameters needs to be considered, including both geometric parameters as well as parameters associated with combustor operation, for instance use of alternative fuels as a means to reduce NOx emissions. The significance of the innovation is that it addresses NASArsquo;s core needs for an economically feasible and environmentally acceptable propulsion technology suitable for a supersonic commercial aircraft. Historically, commercial supersonic transport has received significant opposition with respect to economic viability (e.g., due to excessive fuel consumption) and environmental impact, both in terms of sonic boom and noise generation for communities along the flight path as well as negative effects on the climate and on public health.