A comparison of the performance of 1st order and 2nd order turbulence models when solving the RANS equations in reproducing the liquid film length unsteady response to momentum flux ratio in Gas-Centered Swirl-Coaxial Injectors in Rocket Engine Applications
Abstract
In liquid rocket combustion devices, mixture formation is one of the most important processes because it determines combustion efficiency, stability, and heat transfer characteristics. The swirling gas and liquid flows in Gas-Centered Swirl-Coaxial Injectors (GCSC) injectors lead to high-quality atomization achieved but with some drawbacks of non-uniformity of flow intensity and mixture composition. We are currently performing numerical simulations in GCSC Injectors geometries that have exhibited some spray non-uniformities when tested at particular operating conditions. Based on validations of previous work in simulations of a round jet, we solve the unsteady RANS equations with the well-known VOF model for the handling of the liquid and gas phases while comparing the performance of two 1st order turbulence models (k-epsilon and k-omega) and one 2nd order turbulence model (RSM). The main objective is to evaluate their ability to reproduce the non-dimensional fuel (liquid) film length response to momentum flux ratio. Preliminary results indicate that the Reynolds Stress Model predictions are comparable to those obtained with the Standard k-epsilon model, nevertheless the former is capable of predicting some liquid-gas instabilities and shedding frequencies that the latter is not able to capture. When compared to the actual experiments, all turbulent models un-der-predict the liquid film length, but the performance of the Standard k-omega model is rather questionable.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 07, 2012
- Accession Number
- ADA576475
Entities
People
- A. Himansu
- L. A. Villasmil
Organizations
- Air Force Research Laboratory