Nelson P. Longmire

University of New Mexico | UNM · Department of Mechanical Engineering

Flows in liquid propellant rocket engines (LRE) are characterized by high pressures and extreme temperature ranges, resulting in complex fluid behavior that requires elaborate thermo-physical models. In particular, cubic equations of state and dedicated models for transport properties are firmly established for LRE simulations as a way to account f...

In propulsion and power systems, operating pressures are increasing to improve cycle efficiency, often reaching conditions that approach or exceed the thermodynamic critical pressure of the working fluid. A known phenomenon that occurs at supercritical pressures is supercritical heat transfer deterioration (HTD). Although this phenomenon is well st...

In this paper, a dataset of wall-resolved large-eddy simulations of cryogenic hydrogen at supercritical pressure and different values of wall heat flux is presented. The aim is to provide a reference dataset for wall-function development under trans- and supercritical conditions, such as those found in liquid rocket engine applications. The employe...

View Video Presentation: https://doi.org/10.2514/6.2022-0339.vid In this contribution a database of wall-resolved LES of cryogenic hydrogen at 5 MPa at different values of wall heat flux is presented. The employed numerical framework is a pressure-based segregated low-Mach number approach based on an equation-of-state independentformulation. The WA...

View Video Presentation: https://doi.org/10.2514/6.2022-0677.vid In many systems, from rocket engines to concentrated solar power, pressures are increased to increase efficiency, thus resulting in these systems operating at supercritical pressures. A crucial step in the design of rocket engines and power systems is to simulate these processes with...

View Video Presentation: https://doi.org/10.2514/6.2021-3593.vid An important aspect for the design of rocket engines is the need to accurately model and simulate the injection and regenerative cooling processes. These processes typically occur at supercritical pressures. Modeling these processes with CFD is challenging, as it is hard to accurately...

Regenerative cooling in high-performance engines requires propellants to be at high pressures. Fluids under these supercritical conditions have drastic changes to their thermodynamic properties which can affect how they perform in the regenerative cooling process, including phenomena such as heat transfer deterioration. Modeling these processes wit...