Simulation of Cavitating Inducer in Rocket Engine Turbopump

2005 ◽  
Author(s):  
Toshiya Kimura ◽  
Yoshiki Yoshida ◽  
Mitsuru Shimagaki
Keyword(s):  
Rocket Engine ◽  
Dynamic Change ◽  
Model Parameters ◽  
Cavitating Flows ◽  
Cavitation Model ◽  
Cfd Simulations ◽  
Two Phase ◽  
Cavity Structure ◽  
Liquid Rocket ◽  
Suction Performance

CFD simulations were applied to cavitating flows around an inducer of a liquid rocket engine turbopump. Unsteady simulations were performed for the full 3D model of an inducer using a cavitation model. The inducer has been tested with water in the cavitation tunnel at JAXA-KSPL to examine suction performance and unsteady cavitation phenomena such as rotating cavitation and cavitation surge. Experiments were conducted under various flow conditions to examine a break-down point of the suction performance and unsteady cavitation phenomena. They have suggested that the casing geometry affected the onset of unsteady cavitation phenomena. Simulations were, therefore, performed for various cavitation numbers. The steady state was firstly calculated without a cavitation model, and then the unsteady calculation was done with the bubble two-phase flow model as a cavitation model. The effect of different model parameters on cavity structure was also examined. In the calculated results, it was clearly observed that the cavity structure grew on the blade surface and accompanied with vortices. These cavities showed dynamic change of their shapes as the rotation of the inducer. The calculated head coefficient showed decrease for small cavitation numbers with similar gradient to that observed in the experiment.

Numerical study of cavitating flow over hydrofoil in the presence of air

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Włodzimierz Wróblewski ◽  
Krzysztof Bochon ◽  
Mirosław Majkut ◽  
Krzysztof Rusin ◽  
Emad Hasani Malekshah
Keyword(s):  
Numerical Study ◽  
Cavitating Flow ◽  
Cavitation Model ◽  
Two Phase ◽  
Content Type ◽  
Flow Simulations ◽  
Cavity Structure ◽  
Dynamic Forces ◽  
High Dynamic ◽  
The Impact

Purpose The presence of air in the water flow over the hydrofoil is investigated. The examined hydrofoil is ClarkY 11.7% with an angle of attack of 8 deg. The flow simulations are performed with the assumption of different models. The Singhal cavitation model and the models which resolve the non-condensable gas including 2phases and 3phases are implemented in the numerical model. The calculations are performed with the uRANS model with assumption of the constant temperature of the mixture. The two-phase flow is simulated with a mixture model. The dynamics and structures of cavities are compared with literature data and experimental results. Design/methodology/approach The cavitation regime can be observed in some working conditions of turbomachines. The phase transition, which appears on the blades, is the source of high dynamic forces, noise and also can lead to the intensive erosion of the blade surfaces. The need to control this process and to prevent or reduce the undesirable effects can be fulfilled by the application of non-condensable gases to the liquid. Findings The results show that the Singhal cavitation model predicts the cavity structure and related characteristics differently with 2phases and 3phases models at low cavitation number where the cavitating flow is highly dynamic. On the other hand, the impact of dissolved air on the cloud structure and dynamic characteristic of cavitating flow is gently observable. Originality/value The originality of this paper is the evaluation of different numerical cavitation models for the prediction of dynamic characteristics of cavitating flow in the presence of air.

scholarly journals Numerical Analysis of Self-Excited Combustion Instabilities in a Small MMH/NTO Liquid Rocket Engine

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Jianxiu Qin ◽  
Huiqiang Zhang
Keyword(s):  
Droplet Size ◽  
Mass Fraction ◽  
Rocket Engine ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Liquid Rocket Engine ◽  
Combustion Instabilities ◽  
Pressure Oscillations ◽  
Two Phase ◽  
Liquid Rocket

Combustion instabilities in a small MMH/NTO liquid rocket engine used for satellite attitude and course control are numerically investigated. A three-dimensional Navier-Stokes code is developed to simulate two-phase spray combustion for cases with five different droplet Sauter Mean Diameters. As the droplet size increases from 30 microns to 80 microns, pressure oscillations are stronger with larger amplitudes. But an increase of the droplet size in the range of 80 microns to 140 microns indicates a reduction in the amplitudes of pressure oscillations. This trend is the same as the Hewitt criterion. The first tangential (1T) mode and the first longitudinal (1L) mode self-excited combustion instabilities are captured in the 60-micron and 80-micron cases. Abrupt spikes occur in the mass fraction of MMH and coincide with abrupt spikes in the mass fraction of NTO at the downstream regions just adjacent to the impinging points. Thus, local combustible high-dense mixtures are formed, which result in quasiconstant volume combustion and abrupt pressure spikes. The propagation and reflection of pressure waves in the chamber stimulate the combustion instability. When the droplet size is too small or too large, it is difficult to form local high-dense premixtures and combustion is stable in the chamber.

scholarly journals Computational and experimental study on supersonic film cooling for liquid rocket nozzle applications

2015 ◽  
Vol 19 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Vishnu Vijayakumar ◽  
Jagadish Pisharady ◽  
P. Balachandran
Keyword(s):  
Computational Model ◽  
Film Cooling ◽  
Fluid Dynamic ◽  
Rocket Engine ◽  
Nozzle Wall ◽  
Cfd Simulations ◽  
Combustion Gas ◽  
Film Cooling Effectiveness ◽  
Liquid Rocket ◽  
Secondary Injection

An experimental and computational investigation of supersonic film cooling (SFC) was conducted on a subscale model of a rocket engine nozzle. A computational model of a convergent-divergent nozzle was generated, incorporating a secondary injection module for film cooling in the divergent section. Computational Fluid Dynamic (CFD) simulations were run on the model and different injection configurations were analyzed. The CFD simulations also analyzed the parameters that influence film cooling effectiveness. Subsequent to the CFD analysis and literature survey an angled injection configuration was found to be more effective, therefore the hardware was fabricated for the same. The fabricated nozzle was later fixed to an Air-Kerosene combustor and numerous sets of experiments were conducted in order to ascertain the effect on film cooling on the nozzle wall. The film coolant employed was gaseous Nitrogen. The results showed substantial cooling along the walls and a considerable reduction in heat transfer from the combustion gas to the wall of the nozzle. Finally the computational model was validated using the experimental results. There was fairly good agreement between the predicted nozzle wall temperature and the value obtained through experiments.

scholarly journals Estimating model parameters of liquid rocket engine simulator using data assimilation

2020 ◽  
Vol 177 ◽  
pp. 373-385
Author(s):  
Daiwa Satoh ◽  
Seiji Tsutsumi ◽  
Miki Hirabayashi ◽  
Kaname Kawatsu ◽  
Toshiya Kimura
Keyword(s):  
Data Assimilation ◽  
Rocket Engine ◽  
Model Parameters ◽  
Liquid Rocket Engine ◽  
Using Data ◽  
Liquid Rocket

scholarly journals Influence of the Cavitation Model on the Simulation of Cloud Cavitation on 2D Foil Section

2008 ◽  
Vol 2008 ◽  
pp. 1-12 ◽  
Author(s):  
S. Frikha ◽  
O. Coutier-Delgosha ◽  
J. A. Astolfi
Keyword(s):  
Void Fraction ◽  
Analytical Study ◽  
Physical Models ◽  
Model Parameters ◽  
Source Terms ◽  
Cavitating Flows ◽  
Cavitation Model ◽  
Cloud Cavitation ◽  
Flow Configurations ◽  
And Behavior

For numerical simulations of cavitating flows, many physical models are currently used. One approach is the void fraction transport equation-based model including source terms for vaporization and condensation processes. Various source terms have been proposed by different researchers. However, they have been tested only in different flow configurations, which make direct comparisons between the results difficult. A comparative study, based on the expression of the source terms as a function of the pressure, is presented in the present paper. This analytical approach demonstrates a large resemblance between the models, and it also clarifies the influence of the model parameters on the vaporization and condensation terms and, therefore, on the cavity shape and behavior. Some of the models were also tested using a 2D CFD code in configurations of cavitation on two-dimensional foil sections. Void fraction distributions and frequency of the cavity oscillations were compared to existing experimental measurements. These numerical results confirm the analytical study.

scholarly journals Application of Large Eddy Simulation to Predict Underwater Noise of Marine Propulsors. Part 1: Cavitation Dynamics

2021 ◽  
Vol 9 (8) ◽  
pp. 792
Author(s):  
Julian Kimmerl ◽  
Paul Mertes ◽  
Moustafa Abdel-Maksoud
Keyword(s):  
Tip Vortex ◽  
Test Cases ◽  
Cavitating Flows ◽  
Two Phase ◽  
Sound Sources ◽  
Radiated Noise ◽  
Eddy Simulation ◽  
Cavity Structure ◽  
Large Eddy ◽  
Free Running

Marine propulsors are identified as the main contributor to a vessel’s underwater radiated noise as a result of tonal propeller noise and broadband emissions caused by its induced cavitation. To reduce a vessel’s signature, spectral limits are set for the propulsion industry, which can be experimentally obtained for a complete vessel at the full-scale; however, the prediction capability of the sound sources is still rudimentary at best. To adhere to the regulatory demands, more accurate numerical methods for combined turbulence and two-phase modeling for a high-quality prediction of acoustic sources of a propeller are required. Several studies have suggested implicit LES as a capable tool for propeller cavitation simulation. In the presented study, the main objective was the evaluation of the tip and hub vortex cavitating flows with implicit LES focusing on probable sound source representation. Cavitation structures for free-running propeller test cases were compared with experimental measurements. To resolve the structure of the tip vortex accurately, a priory mesh refinement was employed during the simulation in regions of high vorticity. Good visual agreement with the experiments and a fundamental investigation of the tip cavity structure confirmed the capability of the implicit LES for resolving detailed turbulent flow and cavitation structures for free-running propellers.

Two-phase flow characteristics of liquid oxygen flow in low pressure liquid rocket engine

Cryogenics ◽  
2004 ◽  
Vol 44 (6-8) ◽  
pp. 493-500 ◽  
Author(s):  
Namkyung Cho ◽  
Seunghan Kim ◽  
Youngmog Kim ◽  
Sangkwon Jeong ◽  
Jeheon Jung
Keyword(s):  
Two Phase Flow ◽  
Rocket Engine ◽  
Flow Characteristics ◽  
Low Pressure ◽  
Oxygen Flow ◽  
Liquid Oxygen ◽  
Liquid Rocket Engine ◽  
Phase Flow ◽  
Two Phase ◽  
Liquid Rocket

Sensitivity Evaluation of a Transport-Based Turbulent Cavitation Model

2003 ◽  
Vol 125 (3) ◽  
pp. 447-458 ◽  
Author(s):  
Rajkumar Vaidyanathan ◽  
Inanc Senocak ◽  
Jiongyang Wu ◽  
Wei Shyy
Keyword(s):  
Volume Fraction ◽  
Transport Model ◽  
Navier Stokes ◽  
Model Parameters ◽  
Cavitating Flows ◽  
Cavitation Model ◽  
Phase Volume Fraction ◽  
Sensitivity Evaluation ◽  
Sensitivity Studies ◽  
The Difference

A sensitivity analysis is done for turbulent cavitating flows using a pressure-based Navier-Stokes solver coupled with a phase volume fraction transport model and nonequilibrium k-ε turbulence closure. Four modeling parameters are assessed, namely, Cε1 and Cε2, which directly influence the production and destruction of the dissipation of turbulence kinetic energy, and Cdest and Cprod, which regulate the evaporation and condensation of the phases. Response surface methodology along with design of experiments is used for the sensitivity studies. The difference between the computational and experimental results is used to judge the model fidelity. Under noncavitating conditions, the best selections of Cε1 and Cε2 exhibit a linear combination with multiple optima. Using this information, cavitating flows around an axisymmetric geometry with a hemispherical fore-body and the NACA66(MOD) foil section are assessed. Analysis of the cavitating model has identified favorable combinations of Cdest and Cprod. The selected model parameters are found to work well for different geometries with different cavitation numbers for attached cavity. It is also confirmed that the cavitation model parameters employed in the literature are within the range identified in the present study.

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