Quasi-One-Dimensional Flow Method for Nuclear Thermal Propulsion Simulator Design

Quasi-One-Dimensional flow methods are commonly used to solve flow situations that have multiple driving influences, i.e. heat transfer, area change, and friction. They hold advantages over other computational fluid dynamics methods due to their much lower computational costs and overall simplicity. Typically, these methods are limited in their ability to solve flows due to the simplifying assumptions used. In this model, a simple heat transfer calculation is combined with NASA’s Chemical Equilibrium with Applications to constantly update chemical properties within the simulation. In this thesis, a quasi-one-dimensional model including these additions is developed and applied to a NTP simulator design problem. Together, these modifications allow for more complex flows to be analyzed, including those with multiple gas species. The results of the study compare favorably with analytical flow solutions of verification cases. The combined system analysis shows realistic results and expected flow rates compare well with hand calculations. The level of accuracy is acceptable for initial design studies and trade-off comparisons. The methods utilized here apply to more widespread flow cases as well, with some slight adjustment of the model and assumptions used. This study demonstrates the continued usefulness of generalized flow methods despite the continuously declining cost of processing power. The code and method presented can easily be adapted for use in other design efforts and further research.