An inducer is a key component in cryogenic pump to improve its cavitation performance. The thermodynamic effects of the medium make flow extremely complicated. For this reason, it crucial investigate which equipped upstream pump. In paper, isothermal model modified based on law heat conduction, and developed by considering effects. turbulence also account for compressibility flow. methods numerical calculations are performed influence inducer. spatio-temporal evolution cryogen clarified....

Axial flow pumps possess a unique structure where there must be clearances between the impeller and piping wall, usually not exceeding 0.1% of diameter. Despite small size clearance, internal micro-vortex structures have non-negligible impact on main field impeller. Under action pressure difference suction surfaces blades, some fluids form high-energy jets in tip clearance area, known as leakage vortices (TLVs). TLV interacts with field, exerting significant state, energy loss, hydraulic...

For the tip-leakage cavitating flow, existence of both interface and microbubbles at scales separated by orders magnitude makes it difficult to be comprehensively reproduced numerical modeling. This work aims develop a multiscale model that directly resolves large-scale cavities models small discrete bubbles. The volume fluid (VOF) method Schnerr–Sauer cavitation are first adopted represent phase field water vapor from macroscale point view. A bubble (DBM) based on Lagrangian formulation is...

Cavitation as a form of unsteady flow within centrifugal pumps can cause the reduced performance pumps, disordered internal regimes, and loss. The present criterion used for determining occurrence cavitation is 3% head drop. However, in most cases, pump already occurs with less than 1%–2% drop due to significant changes status. To examine changing patterns characteristics degree deepens early stage when curve does not show fluctuation, this paper focuses on low specific speed analyze...

We have employed the large eddy simulation (LES) approach to investigate cavitation noise characteristics of an unsteady cavitating flow around a NACA66 (National Advisory Committee for Aeronautics) hydrofoil by employing Eulerian-Lagrangian based multiscale model. A volume fluid (VOF) method simulates cavity, whereas Lagrangian discrete bubble model (DBM) tracks small bubbles. Meanwhile, is determined using Ffowcs Williams-Hawkings equation (FW-H). analysis has shown that, in comparison...

Due to interstitial flow and medium heat transfer, canned motor pumps (CMPs) are more susceptible cavitation than other pumps. For CMP-driven liquid cooling systems, can reduce the transfer capability of system or even lead overheating failure. Therefore, it is necessary monitor status inside CMP. In response issues such as low computational efficiency weak anti-interference capabilities, a new recognition method proposed in this article. First, complete ensemble empirical mode decomposition...

Centrifugal pumps, which are essential for the transfer of fluids, extensively utilized in industries like aerospace and new energy vehicles. These fields require pumps to meet rigorous standards terms reliability, efficiency, vibrational noise while also imposing stringent restrictions on their size weight. Therefore, achieving optimal performance both efficiency reduction centrifugal limited space poses a considerable difficulty. This study investigates impact different volute area ratios...

Unstable or flat head-flow curves can cause problems in parallel operations systems. Despite the considerable efforts that have been devoted to study of curve instability single-stage centrifugal pumps with volute casing, such phenomenon is not sufficiently understood. In this study, we investigated variation hydraulic losses based on relationship between velocity distribution and entropy generation fields. Steady-state unsteady simulations were obtained for a pump an impeller outlet...

Boosted methanol production over MnO x /ZrO 2 catalyst could be achieved via plasma-assisted catalytic CO hydrogenation at ambient temperature and pressure.

Due to high power consumption and low energy efficiency of the hydrogenation feed multistage pump, conducting structural optimization design reducing losses for this pump is necessary. In study, an method based on particle swarm (PSO) algorithm least squares support vector regression (LSSVR) surrogate model proposed. The head are taken as objectives two impellers carried out. Through model, increased by 3.99% 2.91%, respectively. It found that optimized impeller has more stable flow...

Sheet-to-cloud cavitation in a Venturi pipe is investigated experimentally and numerically this work. The multiscale vapor structures are simulated by Eulerian–Lagrangian modeling. volume of fluid method with adaptive mesh refinement employed to capture the macroscale cavity features, utilizing large eddy simulation approach. results sensitivity study demonstrate that second-order capable capturing phase details shedding behaviors. A comparison experimental reveals mechanisms different types...

The multi-stage submersible pump is a power conveyor for low-temperature media, which conveyed by the rotating of centrifugal impellers. In this study, impellers were optimized to improve efficiency under premise constant total blade load and head. Based on analysis performance flow each stage 18-stage pump, optimization scheme composed first stage, middle last was determined. outlet angle, average wrapping angle difference selected as parameters through Plackett–Burman experimental design...

Pumps as turbines (PATs) are used in petroleum and chemical industries to recover high-pressure residual energy. Multistage PATs allow for a wider energy recovery interval range of applications. However, because multistage centrifugal pumps were not originally designed turbine conditions, complex pressure fluctuations occur, impacting the stable operation performance PAT. Pressure fluctuation is essentially wave, by analogy with wave intensity definition, quantified using flow density,...

For understanding tip-leakage cavitating flow features, the present work aims to implement a multiscale model comprehensively reproduce complicated phase structure. The volume of fluid (VOF) interface capturing method is applied simulate macroscale cavities, while discrete bubble using Lagrangian formulation newly developed take microscale bubbles into account. Schnerr–Sauer cavitation incorporated VOF calculate mass transfer rate between phases from point view. bubbles, simplified...