This study employs the two-dimensional proper orthogonal decomposition approach to analyze pressure, vapor fraction, and streamwise velocity flowfields of partial cavity oscillation. The interrelations among mode, energy ratio, temporal coefficient, flowfield reconstruction are thoroughly examined, thereby augmenting comprehension cavitating flow mechanism bubble dynamics. It is found that first modes contain 56.31%, 36.37%, 31.81% energy, respectively; decrease in ratio results variation...

This paper introduces several compressible computational fluid dynamics (CFD) methods and assesses their ability to simulate typical sheet-to-cloud cavitating flow around a hydrofoil. More precisely, the Tait equation of state is used describe density water, while ideal gas model vapor. The first method assumes that cavitation multiphase with isothermal conditions, meaning it exhibits compressibility. Based on method, second third take into account thermal energy total equations,...

Double-suction centrifugal pumps are widely used in industrial and agricultural applications since their flow rate is twice that of single-suction with the same impeller diameter. They usually run for longer, which makes them susceptible to cavitation, putting downstream components at risk. A fast approach predicting Net Positive Suction Head required was applied perform a multi-objective optimization on double-suction pump. An L32 (84) orthogonal array designed evaluate 8 geometrical...

The recent advances in centrifugal pump design do not only require a better suction performance but also there have been attempts to reduce time at lower cost. traditional trial-and-error optimization method, however, depends on the designer's experience, which requires longer cycles. This is because computational process of calculating net positive head required (NPSHr) involves several calculation steps and this consumes lot time. An investigation was therefore carried out test novel NPSHr...

Researches have over the past few years been applying optimization algorithms to quickly find optimum parameter combinations during cavitation design. This method, although better than traditional trial-and-error design consumes lots of computational resources, since it involves several numerical simulations determine critical point for each test case. As such, Traditional method NPSHr prediction was compared a novel and alternative approach in an axially-split double-suction centrifugal...

Abstract This study employs an incompressible homogeneous flow framework with a transport-equation-based cavitation model and shear stress transport turbulence to successfully reproduce the unsteady cavitating around three-dimensional hydrofoil. Cavity growth, development, break-off during periodic shedding process are adequately reproduced match experimental observations. The predicted frequency is very close value of 23 ms. By monitoring motions seeding trackers, growth-up attached cavity...

Performance improvement is very important to the energy saving of pumps and industrial pumping systems. To increase efficiency at design point, an artificial neural network applied construct a non-linear function with high accuracy between optimization objective variables impeller, then particle swarm used globally optimize mathematical model. A database consists 200 sets impellers generated from Latin Hypercube Sampling method corresponding efficiencies obtained numerical simulation. whole...

The significance of renewable energy sources, such as generation viable output from small hydropower (SHP), has been great concern with several measures being taken to alleviate the serious shortfall electricity supply in rural areas sub-Saharan Africa. SHP can play very important roles electrification areas. potential for is typically found away more populous and a suitable source purpose electrification. It be used either standalone power or hybrid system other sources. Depletion fossil...

A laminar–turbulent transition subject to a freestream turbulence involves highly complex flow mechanisms, which have received considerable interest in the past decades. Accurately predicting such physical phenomena is significantly challenging using computational fluid dynamics solvers, particularly industrial engineering applications. In this study, capability of two transitional models—k−kl−ω and k−ω−γ−Re˜θt—to predict T3A plate scenario was revisited. First, predicted boundary layer data...