Modeling an unsteady flow is an important problem in pressurized pipeline systems. Depending on the dimensions and properties of the fluid and pipeline material, the generation of hydraulic transient issues and their spatiotemporal variation patterns can be different. To address the water hammer problem without scale issues in pipeline systems, this study developed a dimensionless impedance method

A procedure for the treatment of tricuspid regurgitation through membrane insertion has been developed recently. However, membrane optimization is required to balance treatment effectiveness with valve damage. This optimization must be performed based on hemodynamic analyses, using the computational fluid dynamics method. The objectives of this study were to analyze hemodynamic features and provide

We investigated differences in haemodynamic forces between carotid arteries that underwent primary closure (PC) or patch angioplasty (PA) using computational fluid dynamics (CFD). A total of 30 subjects were enrolled in this study, consisting of 10 subjects who underwent PC, 10 who underwent PA and 10 healthy subjects. Three-dimensional models of carotid arteries were reconstructed using patient-specific

Rubber glove manufacturing requires improvements in the curing process. In this study, the forced convection of hot airflow past a hand-shaped former, which has a typical shape in the rubber glove manufacturing process, was examined. A former model consisting of five fingers, palm, dorsum, and wrist was separated to investigate the convective heat transfer of the individual parts by OpenFOAM. The study

Vortex detection plays a fundamental role in turbulence research and engineering problems. However, due to the lack of a mathematically rigorous vortex definition, as well as the absence of any vortex-oriented database, both traditional and machine learning detection methods achieve only limited performance. In this paper, we develop a deep learning model for vortex detection using a weak supervision

Engineering systems operating under particle-laden turbulent flow regimes, such as slurry pumps, are prone to erosive wear, where the specific conditions of particle impingement are crucial for determining the wear rate of the eroding surface and thus its relevance for the mechanical or hydraulic system. However, the near-wall interactions under turbulent flows impose a challenge for the formulation

It is a considerable challenge to develop a mathematical method for modelling the coupling relationship between the control signal and braking performance in the design and optimization, especially with a highly nonlinear system. The present study thus establishes an integrated CFD-aided method, elaborately proposed based on a 1D/3D co-simulation to accomplish a goal of collaborative calculation between

ABSTRACT The optimization problems are becoming more complicated, requiring new and efficient optimization techniques to solve them. Many bio-inspired meta-heuristic algorithms have emerged in the last decade to solve these complex problems as most of these algorithms may be trapped into local optima and could not effectively solve all types of optimization problems. Hence, researchers are still trying

This research describes the dynamic behavior of an isolated slug driven by pressurized air in a voided line with an end orifice. A three-dimensional (3D) computational-fluid-dynamics (CFD) model is used to simulate the rapid propulsion and impact at the orifice for given slug length and driving air pressure, and is validated against experimental data. New mechanisms are observed: (i) the driving air

Most turbine designs are based on the continuous rotating turbine structure. In this paper, a novel hydraulic balanced turbine (HBT) with a symmetrical blade structure that can be used in a hydro-environment is proposed. The turbine, which uses the hydraulic impact of the nozzle jet and balanced turbine blade design in stability control, could be used to control stability in certain applications, e

To analyze the complex spatiotemporal evolution law of the high-speed jet flow field in a liquid-ring pump ejector, both the classic and spectral proper orthogonal decomposition (SPOD) methods were introduced to decompose the transient flow field based on the numerical large eddy simulation. The proper orthogonal decomposition (POD) reduced order model (ROM) of the complex flow in the ejector was established

Blind tees are widely used in subsea pipelines to enhance the mixing conditions of oil and gas products, but their structural design still relies on experience. In this paper, a series of numerical investigations have been carried out on blind-tee pipes in order to develop an in-depth understanding of their mixing mechanism and clarify the effects of blind-tee structures on the pipe flow. Firstly,

The initial space settings of suitable environments for plants strongly affect the mutual feedback evolution of the river landscape and terrestrial plants. Thus, based on the morphological characteristics of newly-defined systematic out-branching channels in nature, this study performs an effective simulation of the flow of a designed moderately curved bend with a single short branch. The practice-based

ABSTRACT Hydrological drought forecasting is a key component in water resources modeling as it relates directly to water availability. It is crucial in managing and operating dams, which are constructed in rivers. In this study, multiple extreme learning machines (ELMs) are utilized to forecast hydrological drought. For this purpose, the standardized hydrological drought index (SHDI) and standardized

The tubeless vortex reducer was used to reduce the pressure drop in a cavity with radial inflow. In previous studies, the mechanism of vortex breakdown in tubeless vortex reducers was not clear, and there was a lack of direct guidance for engineering design. In this paper, we studied the vortex and pressure in the cavity in detail by large-eddy simulation (LES) and experiments. A mathematical model

To investigate the hard-to-measure complex flow in a squirrel-cage fan, a slice model was established in the present study to perform a partial large eddy simulation calculations on an r-θ sectional flow field instead of the large-scale and time-consuming full three-dimensional flow calculations. The method used to build the slice model was first introduced, and then the model was verified by the results

The wind resistance of a model of a large container ship was investigated experimentally and numerically under various conditions to investigate the aerodynamic performance and identify approaches for reducing wind resistance. The container ship model with and without six types of forecastle fairing was tested in a wind tunnel under conditions of full load and various uneven loads in different wind

The hydraulic joint is the key driving component of a robot. To reduce the joint size of the hydraulic robot, and improve the control accuracy and dynamic response performance, this paper proposes a novel joint structure and control method of a ball double-screw hydraulic robot. Using ball and circular arc spiral groove transmission, the hydraulic joint has a small transmission friction coefficient

A gas journal microbearing and the corresponding rotor-bearing system are studied both theoretically and experimentally for their application in the high-speed air compressor of fuel cell vehicles. The gas microbearing is proved to provide reliable support for the rotor, as it shows both static and dynamic pressure effects under the high operating speed of the on-board air compressor. In order to realize

In pursuit of stable operation in thermal hydraulic engineering, this paper researches two-phase flow through tube bundles by the lattice Boltzmann method. The single-relaxation-time lattice Boltzmann model and the multicomponent, multiphase pseudo-potential lattice Boltzmann model are adopted. Specifically, the two-phase flow past double-tandem circular cylinders, double-parallel circular cylinders

The suspended sediment load (SSL) is one of the major hydrological processes affecting the sustainability of river planning and management. Moreover, sediments have a significant impact on dam operation and reservoir capacity. To this end, reliable and applicable models are required to compute and classify the SSL in rivers. The application of machine learning models has become common to solve complex

Particles and condensing vapors contribute to the contamination of optical components of solar thermochemical reactors including windows and secondary concentrators and result in severe reactor performance deterioration. We propose an impinging-jet solar reactor in a distinctive topology to enhance aerodynamic-aided window protection. The vector fields on the two-dimensional inner surfaces of the impinging-jet

Swirling gas flow is an important topic of research that helps in the design of rockets, atomizers,and gas turbine combustors. In the present work, swirl flow inside annular geometries with constant and varying cross-sectional areas are examined using computational fluid dynamics (CFD). Effects of changing the flow and geometric parameters on the swirl behaviour were studied. Reynolds number was found

The launch vehicle will experience extreme acoustic environment at lift-off, which will cause the invalidation and destruction of the aerospace equipment, and reducing noise is of great significance for improving launch safety. In this paper, the numerical simulation of gas–liquid two-phase flow and its acoustic field is carried out, and the flow field is simulated by the discrete phase model (DPM)

Most mixed-flow pumps obtain a saddle-like Q-P curve with a backflow, owing to the increased incidence angle at low flow rates. The backflow was developed near the shroud and followed downstream again at its end to form a recirculating flow. The rotating stall, which could be a part of the recirculating flow, followed the impeller’s rotational direction, and its properties affected the local stability

Dropshafts with tangential intakes are common structures in urban water drainage systems. The plunging and vortex flowpatterns are the typical flow regimes, which are mainly affected by the tangential intake design and flood discharge. However, thehydraulic flow transition between vortex and plunging flow patterns has received little attention, which may affect the dropshaftoperation during extreme

Counter-rotating axial-flow compressor (CRAC) is a promising technology to increase the thrust-to-weight ratio of aero-engines. Self-recirculating casing treatment (SRCT) is selected to explore its stability enhancement capacity in the CRAC. In the present work, an effective SRCT is designed by the design of experiment method, and the stability improvement potential of the SRCT and its mechanism of

To reduce the crosswind effect on high-speed trains, in this paper, by using the Improved Delayed Detached Eddy Simulation (IDDES) method and the SST k−ω turbulence model, a novel blowing measure is studied and compared by considering different positions of blowing slots on the train surface. The concerned blowing positions on the train surface include the top position (Top); windward side (WWS): the

Saturated hydraulic conductivity (Ks) is an important soil characteristic that controls water moves through the soil. On the other hand, its measurement is difficult, time-consuming, and expensive; hence Pedotransfer Functions (PTFs) are commonly used for its estimation. Despite significant development over the years, the PTFs showed poor performance in predicting Ks. Using Genetic Algorithm (GA),

A well-designed battery thermal management system (BTMS) can achieve optimal cooling performance with less power consumption than a poorly-designed system. However, it is difficult to use the computational fluid dynamics (CFD) method to perform an effective and optimal design of BTMSs when there are several structural design parameters and multiple evaluation criteria. In this paper, instead of CFD

Cavitation is a challenging flow phenomenon that can adversely affect the hydraulic performance of centrifugal pumps. In this study, numerical investigations were carried out incorporating the Zwart cavitation model derived from Rayleigh–Plesset equation with the Navier–Stokes equations to study a damaged turbofan pump. Pressure fluctuation was analyzed with fast Fourier transform (FFT) in both non-cavitation

Stenosis of the cerebral aqueduct (CA) is featured in many studies relating to elevated intracranial cerebral pressures. It also presents a challenging situation to clinicians. Compressive forces play a lead role in pathological situations such as the presence of tumors and hence can cause obstruction to the flow of cerebrospinal fluid (CSF). Because of this barrier, excessive retention of CSF in the

Streamlined weirs, which are a nature-inspired type of weir, have gained tremendous attention among hydraulic engineers, mainly owing to their established performance with high discharge coefficients. Computational fluid dynamics (CFD) is considered as a robust tool to predict the discharge coefficient. To bypass the computational cost of CFD-based assessment, the present study proposes data-driven

In the present study, hydraulic and thermal performances of nano-enhanced drilling muds have been studied across the complex geometry of a rotating polycrystalline diamond compact (PDC) drill bit using computational fluid dynamics techniques. Toward this goal, a robust converging procedure is applied to generate an advanced tetrahedral/prism grid structure using special techniques. We also utilize

In this study, a fluid-structure interaction solver is employed to explore the flow physics of tandem oscillating square bluff bodies by varying the corner radius. Based on previous research, dynamic behavior, and fluid forces only square and circular bluff bodies are chosen for a supplementary investigation. This study investigates the effects of the streamwise displacement, 1.05≤Lx/D≤12.0, of two

In this paper, cyclone separator is proposed for the first time to separate particles according to density, and it is applied to the recovery of lithium iron phosphate (LFP) from spent lithium battery materials for the first time. The effect of the flow field on the motion of injected particles in a cyclone separator is studied by means of computational fluid dynamics (CFD). It is found that there

In this study, the laminar nanofluid flow in the microchannel with a discontinuous-boundary condition was investigated. Considering the slip condition, heat transfer and entropy generation were studied. Different layouts with the discontinuous-boundary condition (i.e. layouts A, B and C) were introduced and compared with the basic microchannel (microchannel with the continuous-boundary condition).

Air injection is an effective method to eliminate flow separation and improve blade loading in compressors. In existing studies on unsteady air injection, achieving a better control effect than steady injection with lower injection consumption is a major difficulty and challenge. In this work, pulsed endwall air injection (PEAI) was carried out numerically in a highly loaded compressor cascade under

Based on numerical simulations, the heat transfer and flow field of a turbine vane are analyzed and the film cooling is improved. The optimization objective is increasing the overall cooling effectiveness with cascade pressure loss factors staying almost unchanged. Thus, cylindrical film holes were replaced by laidback holes and V-crater holes. To analyze the effect of structural adjustment on the

Porous media structures have been proposed as an interesting solution on the design of high-temperature volumetric heat exchangers and sensible thermal energy storage devices. The wide exchange area between the solid matrix and the fluid offers the possibility to reach higher conversion efficiencies, particularly on applications of high-temperature (∼1000°C) gases. Nevertheless, the presence of the

Soil moisture (SM) is of paramount importance in irrigation scheduling, infiltration, runoff, and agricultural drought monitoring. This work aimed at evaluating the performance of the classical ANFIS (Adaptive Neuro-Fuzzy Inference System) model as well as ANFIS coupled with three bio-inspired metaheuristic optimization methods including whale optimization algorithm (ANFIS-WOA), krill herd algorithm

A feature of reverse circulation pneumatic down-the-hole (DTH) hammer drilling system is its ability to reduce the emission of respirable dust which is known to be harmful to drilling workers and equipment. The enhanced dust control performance of the drilling system requires better understanding and insight into the airflow behavior at the bottom of the borehole. To investigate the transportation

This paper proposes a prediction strategy for the hydrodynamic performance of bionic fish. The major challenges are meshing and building prediction model. The NACA0012 airfoil is used to replace the fish driven by the body and/or caudal fin (BCF), and a two-dimensional swimming geometric model is constructed. The geometric model is divided into hybrid meshes using the overset mesh method. The classical

Dynamic viscosity of novel generated Copper Oxide (CuO)/Liquid Paraffin nanofluids is obtained experimentally for various temperatures and concentrations. To optimize the empirical process and for cost-efficiency, Feed-Forward Neural Networks (FFNNs) were modeled and compared with Recursive Least Squares (RLS) Fuzzy model. To prepare CuO/ liquid paraffin nanofluids, CuO nanoparticles are dispersed

In this paper, the aerodynamic noise of a centrifugal fan with an eccentric impeller is investigated and analyzed by adopting a hybrid method combining detached-eddy simulation and the acoustic finite element method (FEM). The impeller-eccentric effect of high-speed centrifugal fans, frequently ignored in theoretical studies, is objective in practical engineering applications owing to machining and

The operation of fluid engineering systems is usually governed by a wide range of different parameters. Investigations of the entire parameter spectrum using classical, first-principle based CFD methods are costly with regards to CPU and wall-clock time. Therefore, a near real-time assessment of complex flows using CFD to support the operation is deemed unfeasible. The paper is concerned with methods

The external windshield is a key component in high-speed trains for drag reduction. However, the installation gap between external windshields, which is intended for improving curve-passing ability, could lead to strong aerodynamic instability in train-end area and therefore significant operating risk for train. This study aims to advance this field based on detailed numerical simulation, investigating

The machine learning method of Adaptive Neuro-Fuzzy Inference System (ANFIS) is proposed as a data-driven technique to model the dew point temperature (DPT). The input patterns, of T min, T max, and T mean, are utilized for the training. The results indicate thatANFIS method is capable of identifying data patterns with a high degree of accuracy. However, the approach demonstrates that processing time

Swirling-flow nanobubble generator is an efficient hydrodynamic cavitation method that can continuously produce enormous quantities of bulk nanobubbles. However, the development of hydrodynamic models of nanobubble generation remains challenging and is rarely found in the literature due to the associated modeling complexity. In this work, a hydrodynamic model was developed to predict bubble size distribution

Characterizing and forecasting coastal water quality and spatiotemporal evolution should be significant to coastal ecosystem management. However, high-quality modeling coastal water quality and their spatiotemporal evolutions is rather challenging due to complex dynamic mechanisms especially in a spatially and temporally heterogenous semi-enclosed bay. To this end, this study develops a framework incorporating

Growth of a Cu(In, Ga)Se 2 (CIGS) layer during a selenization process is numerically studied to understand mechanisms for formation of stains on large-area substrates batched. CIGS layers need to be uniformly deposited onto the substrates to obtain even conversion efficiency. However, it is difficult to control growth of large-area CIGS layers due to turbulent thermal-fluid flow leaving stains on the

Oscillating water columns (OWCs) have been studied extensively as promising wave energy converters. Different factors can affect the pneumatic power of OWCs, such as model scaling, turbine damping, and air compressibility. In this study, the heave motion of the OWC was limited by adding friction, and the effect of orifice size on the pneumatic power of an OWC from an unconstrained to a fixed position

Heat transfer and phase change in multiphase media involve complex behavior such as multi-physics coupling, unsteady interfaces, and boundary generation/disappearance. The smoothed particle hydrodynamics (SPH) method is used to simulate multicomponent problems (initially solid material surrounded by a fluid) characterized by heat transfer, solid–liquid phase change, and multiphase flow. First, the

The computational fluid dynamics (CFD) simulation method is commonly used for large-scale computational engineering problems. However, it usually leads to higher computational costs. The deep learning method has gained significant attention in recent years. However, the traditional methods fail to achieve high-precision pixel-level predictions. They are difficult to predict more detailed, multi-scale

A numerical simulation approach is substantiated and verified for predicting the Taylor-Couette flow with an impermeable outer stationary cylinder and porous rotating inner one. An imposed throughflow is considered, supplied via one end of the annular gap and leaving the domain through another gap end (retentate) and from inside of the rotating cylinder (permeate). The flow is typical for dynamic filtration

The effect of pump impeller modification by a new approach, pump impeller shroud trimming (PIST), on the flow field and pump performance is examined both numerically and experimentally. The primary purpose of this study is to investigate the hydraulic performance of single-phase centrifugal pumps, which are refined by the PIST method, with low and medium specific speeds. In this type of shroud trimming

In-pipe water turbines have begun to gain interest for harvesting power on a small scale from pipe networks. However, few studies have addressed the feasibility of installing spherical lift-based helical-bladed turbines in a water supply network. Points such as the pressure drop and generated power remain unexplored. In this study, a three-dimensional numerical model, based on OpenFOAM, is used to

The aerodynamic characteristics of turboprop aircraft are greatly affected by the running propellers. In this paper, propeller slipstream effects on the static lateral-directional stability characteristics of a typical twin-engine turboprop aircraft with clockwise rotating propellers were investigated through unsteady computational fluid dynamics (CFD) simulations and wind tunnel experiments. The propeller

In the present study, two innovative techniques namely, Deep Learning (DL) and Gradient boosting Machine (GBM) models are developed based on a maximum air temperature ‘univariate modeling scheme’ for modeling the monthly pan evaporation (Epan) process. Monthly air temperature and pan evaporation are used to build the predictive models. These models are used for evaluating the evaporation prediction

Investigating the flow characteristics in the cavity by changing the rotor profile of the rotor-stator system is of considerable significance, this paper simplifies clearance flow to rotor-stator cavity flow. The numerical simulation results are compared with the experimental results of the windage torque of the rotor-stator system, and the results show that the accuracy of the numerical calculation