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The Open National Combustion Code (OpenNCC) is applied to the simulation of a realistic combustor configuration (Energy Efficient Engine (E 3)) in order to investigate the unsteady flow fields inside the combustor and around the first stage stator of a high pressure turbine (HPT). We consider one-twelfth (24 degrees) of the full annular E 3 combustor with three different geometries of the combustor exit: one without the vane, and two others with the vane set at different relative positions in relation to the fuel nozzle (clocking). Although it is common to take the exit flow profiles obtained by separately simulating the combustor and then feed it as the inflow profile when modeling the HPT, our studies show that the unsteady flow fields are influenced by the presence of the vane as well as clocking. More importantly, the characteristics (e.g., distribution and strength) of the high temperature spots (i.e., hot-streaks) appearing on the vane significantly alters. This indicates the importance of simultaneously modeling both the combustor and the HPT to understand the mechanics of the unsteady formulation of hot-streaks.

This paper presents a CFD model for simulating the self-pressurization of a large scale liquid hydrogen storage tank. In this model, the kinetics-based Schrage equation is used to account for the evaporative and condensing interfacial mass flows. Laminar and turbulent approaches to modeling natural convection in the tank and heat and mass transfer at the interface are compared. The flow, temperature, and interfacial mass fluxes predicted by these two approaches during tank self-pressurization are compared against each other. The ullage pressure and vapor temperature evolutions are also compared against experimental data obtained from the MHTB self-pressurization experiment. A CFD model for cooling cryogenic storage tanks by spraying cold liquid in the ullage is also presented. The EulerLagrange approach is utilized for tracking the spray droplets and for modeling interaction between the droplets and the continuous phase (ullage). The spray model is coupled with the VOF model by performing particle tracking in the ullage, removing particles from the ullage when they reach the interface, and then adding their contributions to the liquid. Dropletullage heat and mass transfer are modeled. The flow, temperature, and interfacial mass flux predicted by the model are presented. The ullage pressure is compared with experimental data obtained from the MHTB spray bar mixing experiment. The results of the models with only droplet/ullage heat transfer and with heat and mass transfer between the droplets and ullage are compared. NomenclatureA = Area density Greek E = Energy  = Cell value of volume fraction g = Gravity  = Slope limiter h = Surface curvature  = Face value of volume fraction k = Turbulence kinetic energy  = Dynamic viscosity L = Latent heat  = Density M = Molar mass of fluid  = Stress tensor n = Normal vector  = Specific turbulence dissipation rate p, P = Pressure q = Heat flux Subscripts Q  = Heat power i = Interface or phase R = Gas constant il = Liquid side of the interface T = Temperature iv = Vapor side of the interface t = Time sat = Saturation conditions v = Velocity l = Liquid c p = Heat capacity at constant pressure v = Vapor m = Mass p = Particle Downloaded by PRINCETON UNIVERSITY on August 11, 2015 | http://arc.aiaa.org |

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