Influence of thermodynamic effects on rotor–stator cavity flow in liquid oxygen turbopump

Bu, Xuebing; Cong, Hongchuan; Sun, Zhongguo; Xi, Guang

doi:10.1063/5.0137980

Cited by 4 publications

(3 citation statements)

References 40 publications

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“…The inducer and impeller are driven by a gas turbine, and the turbopump rated speed is 30,000 r/ min. Same as the research model employed in reference [45], the main parameters of the turbopump are illustrated in Table 1.…”

Section: Pump Geometry and Experimental Test Rigmentioning

confidence: 99%

“…In this study, the grids were generated via ICEM CFD. Consistent with the grid strategy in reference [45], a hexahedron structure grid with small truncation error and good convergence was selected to discretize all computational domains to ensure the accuracy of the numerical simulation, as shown in Figure 5. The mesh of the narrow gaps was refined, such as the clearance in the shroud cavity and rear cavity, especially the annular gap between the rotating impeller and stationary casing [46].…”

Section: Numerical Strategy and Test Verificationmentioning

confidence: 99%

“…During the exploitation of a new generation launch vehicle, detailed pressure distributions on the rear side of the impeller, which affect the axial thrust characteristics, were obtained via compressible simulation [42][43][44]. Recently, Bu et al studied the thermodynamic effects of liquid oxygen on the flow distributions in the rotor-stator cavities of a cryogenic turbopump [45]. The current researches pay more attention to the influence of thermodynamic effects on the inducer cavitation; however, the influence of the cryogenic medium on the axial thrust needs to be further analyzed.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Influence of Rotating Speeds and Thermodynamic Effects on LOX Turbopump Performance

Fu²,

Cong

et al. 2023

International Journal of Aerospace Engineering

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As a key factor of a reusable turbopump, axial thrust directly determines the reliability of the bears and seals, especially considering the influence of rotational speeds and thermodynamic effects. In this study, numerical simulations and experimental tests were conducted to explore the impact of rotational speeds and the divergences of the turbopump performance with/without the thermodynamic effects. The experimental data obtained at 15000 r/min are in good agreement with the numerical results, illustrating the validity of the numerical model. The results show that the head deviations based on the affinity laws are relatively smaller, only 0.1% difference at normal condition, yet the efficiency increases from 72.5% to 73.8%, which need to be modified through the formula correction. Notably, the axial thrusts acting on impeller are significantly affected by the rotational speeds, and the values at rated flowrate decrease 17.6% after increasing the operating condition to rated speed. The affinity laws are not applicable for obtaining the turbopump axial thrusts under different speeds. Furthermore, due to the changes of the local physical properties, the values of head coefficient and efficiency decrease 2.8% and 1.3% at rated flowrate, respectively, when the thermodynamic effects of liquid oxygen are considered. Meanwhile, the relative variations of axial thrust are between 1.46% and 3.74% within the whole flow range. Finally, an in-depth analysis of the internal flow was conducted through the velocity field and vorticity method. In conclusion, both the rotational speeds and thermodynamic effects significantly affect the performance of a cryogenic turbopump, especially the axial thrust, and the unsteady results of the rotor-stator cavity leakage flow need to be analyzed in the future.

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Section: Pump Geometry and Experimental Test Rigmentioning

confidence: 99%

Section: Numerical Strategy and Test Verificationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Influence of Rotating Speeds and Thermodynamic Effects on LOX Turbopump Performance

Fu²,

Cong

et al. 2023

International Journal of Aerospace Engineering

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The effect of rotor roughness on flow and heat transfer in rotor–stator cavities with different axial gap

Hu,

Yao,

Wang

et al. 2024

Applied Thermal Engineering

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Numerical investigations on the mechanisms of the tip leakage vortex cavitation development in a cryogenic inducer with large eddy simulation

Chen

et al. 2023

Physics of Fluids

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Liquid hydrogen is considered clean energy and is usually pressurized by cryogenic pumps in various industries. To ensure the safe operation of cryogenic pumps, the inducer is installed in front of the pump to improve the impeller inlet pressure but causes cavitation instabilities. This paper aims to investigate the mechanisms of the tip leakage vortex (TLV) cavitating flow in a cryogenic inducer with liquid nitrogen. The large eddy simulations model was used to analyze the thermodynamic effects on the tip leakage vortex cavitation (TLVC). The cavity structure and the pulsation mechanisms of the TLVC were analyzed through the flow characteristics and the vorticity transportation process. The predicted cavitation performance is in good agreement with the experimental measurements. The numerical results showed that the TLVC is suppressed and forms the separation point between the primary TLVC and the secondary TLVC due to the thermodynamic effects. The inhibition rate of the vapor volume fraction at the leading edge is 30%. The pressure fluctuations are caused by the propagation pattern of the detached cavity interacting with the adjacent blade periodically. The velocity triangles near the detached cavity were proposed to reveal the development of the TLVC. It indicates that TLVC instability is caused by the periodic coupling effect of the cavity development, the flow rate magnitude, and the local incidence angle variation. The vorticity transport equation is utilized to investigate the interaction of cavitation and vortex. Comparing the three terms reveals that the stretching and bending term dominates in the vorticity production of the TLV cavitating flow. The dilatation term controls the transportation of vorticity inside the TLV cavity, while the contribution of the baroclinic torque term is negligible in comparison to the other terms. This study provides a reference for optimizing the TLV cavitating flow and instabilities for designing the cryogenic pump.

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Influence of thermodynamic effects on rotor–stator cavity flow in liquid oxygen turbopump

Cited by 4 publications

References 40 publications

Influence of Rotating Speeds and Thermodynamic Effects on LOX Turbopump Performance

Influence of Rotating Speeds and Thermodynamic Effects on LOX Turbopump Performance

The effect of rotor roughness on flow and heat transfer in rotor–stator cavities with different axial gap

Numerical investigations on the mechanisms of the tip leakage vortex cavitation development in a cryogenic inducer with large eddy simulation

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