Numerical Simulations of Single Flow Element in a Nuclear Thermal Thrust Chamber

Abstract

The objective of this effort is to develop an efficient and accurate computational methodology to predict both detailed and global thermo-nuid environments of a single now element in a hypothetical solid-core nuclear thermal thrust chamber assembly, Several numerical and multi-physics thermo-fluid models, such as chemical reactions, turbulence, conjugate heat transfer, porosity, and power generation, were incorporated into an unstructured-grid, pressure-based computational fluid dynamics solver. The numerical simulations of a single now element provide a detailed thermo-fluid environment for thermal stress estimation and insight for possible occurrence of mid-section corrosion. In addition, detailed conjugate heal transfer simulations were employed to develop the porosity models for efficient pressure drop and thermal load calculations.

Thermal Hydraulics Design and Analysis Methodology for a Solid-Core Nuclear Thermal Rocket Engine Thrust Chamber

“…To enhance the temporal accuracy, a second-order backward difference scheme was employed to discretize the temporal terms. Details of the numerical algorithm can be found in [8][9][10][11][12][13].…”

“…By simulating and comparing the computed environments with those of the Small Engine design analysis and available test information from the legacy tests, the lessons learned during Rover/NERVA era may be revitalized and the effect of some important design features may be validated. This Chapter therefore reviews the thermal hydraulics computational methodology developed to help the design of a materials tester [4,6], and the results reported in the design analyses of the Small Engine [7,8]. Figure 1 shows the compu-tational model [7] of the Small Engine that shows the surfaces of the hydrogen inlet duct, a pressure vessel that houses the solid-core reactor, and an exhaust nozzle that provides the thrust.…”

“…A two-pronged approach was conducted to address the aforementioned efforts: a detailed modeling of a single, powered flow element that addresses possible, additional cause of the mid-section corrosion [8], and a global modeling approach that computes the entire thermal flowfield of the Small Engine thrust chamber [7]. The latter links the thrust performance with the effects of power profiles, chemical reactions, and overall heat transfer efficiency.…”

Transient Three-Dimensional Side Load Analysis of Out-of-Round Film Cooled Nozzles

“…Sub-iterations within a time step were used for driving the system of second-order time-accurate equations to convergence. Details of the numerical algorithm can be found in Ref's [18][19][20][21].…”

Transient Side Load Analysis of Out-of-Round Film-Cooled Nozzle Extensions

“…Sub-iterations within a time step were used for driving the system of second-order time-accurate equations to convergence. Details of the numerical algorithm can be found in Ref's [20][21][22][23].…”