This article proposes a novel a magnetophoretic microfluidic device for separation of magnetic microparticles based on size and subsequently carries out simulation-based parametric analysis of the same. The microfluidic device is constructed with two inlets as well as two outlets and employs a soft magnetic element subjected to a uniform magnetic field to create the desired spatially varying magnetic

The thermal environment of four-engine liquid rocket exhaust plume impinging on the flame deflector with different impingement and uplift angles is analysed. The supersonic exhaust gas impinging model was established by using the compressible, multi-component, Reynolds-Averaged Navier-Stokes (RANS) equations with the finite volume method. A comparison between the numerical results and experimental

End of vehicle streamlined head was selected as the installation location, and aerodynamic behavior of trains with and without braking plates was compared to analyze the formation of the braking force and the evolution of the flow field. An IDDES method based on the SST κ–ω turbulence model was used to investigate the unsteady flow, and the numerical algorithm was validated. Results show that the train

In this study, computational fluid dynamics (CFD) was used to investigate the performance of the steam ejector used in refrigeration systems to increase operational flexibility and COP. A 2D-axisymetric model of a two-stage ejector (TSE) was developed and its performance was compared to that of the commonly used single-stage ejector. The SST k-omega (k-ω-sst) model was applied as a turbulence model

In the operation of a nuclear plant system, a distorted inflow of a reactor coolant pump appears owing to the steam generator channel head and multi-bend, leading to the deterioration of pump performance and stability. In the present study, three-dimensional numerical calculations of three model geometries are carried out using block grid technology, with RNG k-ε and DDES model applied in the stea

This paper considers a solution to the serious problem of hydraulic maladjustment in a dynamic flow balance valve for small diameter and low-pressure drop working conditions. The pressure drop compensation coefficient revising method was proposed to optimize the profile line of the valve core variable opening area. The flow rates of the valve before and after optimization under different displacements

High level of tropospheric ozone concentration, exceeding allowable level has been frequently reported in Malaysia. This study proposes accurate model based on Machine Learning algorithms to predict Tropospheric ozone concentration in major cities located in Kuala Lumpur and Selangor, Malaysia. The proposed models were developed using three-year of historical data for different parameters as input

ABSTRACT This paper reports the results of a numerical study on the dynamics of isothermal multiphase fluids using an energy-law-preserving method. A phase-field model is taken into account. Different to previous studies, a continuous finite element technique is used to simulate the Navier-Stokes-Cahn-Hilliard coupled model. A modified discrete energy law of the numerical simulation is derived in detail

ABSTRACT Colloidal particles removal from water is a challenge in surface water treatment. Previously, we suggested an original technique for colloidal particles separation from water based on physical flow manipulation by an oscillating device. Laboratory experiments and 2D numerical simulation indicated that this technology enhances colloidal particles grouping and enables their rapid, simultaneous

Instantaneous gas–liquid flow and distribution have an important influence on the performance of a multiphase pump, especially under the high gas content conditions. How to accurately simulate the complete working cycle of a multiphase pump and reflect the transient oil-gas flow inside the pump cavity are the main difficulties of the study. A three-dimensional whole-cycle numerical simulation has been

This paper aims to investigate the hydrodynamics of a flexible fishlike foil undulating near the vertical sidewall by using numerical simulation. To achieve the research target of this paper, an immersed boundary-lattice Boltzmann method (IB-LBM) was proposed for high Reynolds number fluid flow simulation. The influences of the clearance (0.2L ≤ d ≤ 0.8L, L is the chord length of the fishlike foil)

Underwater vehicles are widely used in underwater detection, and bionic design, e.g. imitating fish, is an important way to improve their hydrodynamic performance. Most research is on the mechanical structure and kinematics of fish-like models, while evolvement rules and hydrodynamic effects of fluid field around fish have not been studied adequately. In this paper, a kinematic model to simulate the

The difference of the aerodynamic influence of two engine models – the Flow Through Nacelle (FTN) and With Powered Nacelle (WPN) – on BWB300 airframe is analyzed by using the 3-D unsteady compressible Reynolds-Averaged Navier-Stokes (RANS) computation. The results indicate that at cruise condition, the engine shape is a primary factor affecting the BWB airframe upper fuselage surface flow, the two

In this study, machine learning methods of artificial neural networks (ANNs), least squares support vector machines (LSSVM), and neuro-fuzzy are used for advancing prediction models for thermal performance of a photovoltaic-thermal solar collector (PV/T). In the proposed models, the inlet temperature, flow rate, heat, solar radiation, and the sun heat have been considered as the input variables. Data

A second order finite-difference numerical method is used to solve the Navier–Stokes equations of incompressible flow, in which the solid body with complex geometry is immersed into the fluid domain with orthogonal Cartesian meshes. To account for influences of the solid body, interactive forces are applied as boundary conditions at Cartesian grid nodes located in the exterior but in the immediate

The emissions of volatile organic compounds (VOCs) from petroleum product tankers potentially represent a significant source of VOCs in port cities. Emission factors are used to estimate the produced VOCs. VOC emissions from transit operations were simulated using a two part model of heat and mass transfer. Using local meteorological data of air temperatures, solar radiation and wind speed, the heat

The work simulates the transport pipeline movement of the marine dynamic environment based on the computational fluid dynamics research method. The present work also studies the influence of the marine dynamic environment on the solid–liquid two-phase flow field in the pipeline. An experimental study on the hydraulic transport flow law of natural gas hydrate pipeline is performed on the experimental

Climate change impacts and adaptations are ongoing issues that are attracting the attention of many researchers. Insight into the wind power potential in an area and its probable variation due to climate change impacts can provide useful information for energy policymakers and strategists for sustainable development and management of the energy. In this study, spatial variation of wind power density

ABSTRACT Distorted inflow caused by the complex structure of the steam generator channel head (SGCH) occurs at the entrance to the reactor coolant pump (RCP) in the AP1000 system, which may generate impeller cracks and result in deterioration of performance and stability. In this paper, to analyze the influence of distorted inflow on flow properties of the RCP, the inflow distortion characteristics

Fluid flows around a pointed object, e.g. the flow around a triangular prism, are often encountered. In this study, numerical simulation of the flow around a triangular prism was carried out using COMSOL Multiphysics® software. Two cases were considered: the entire area of the triangular prism is fixed; and only the center is fixed. The first case is divided into three different flow models according

Idling power loss suppression techniques of hydraulic retarders in non-braking operating conditions are of great significance to improve vehicle driving efficiency. Most proposed idling power loss suppression devices require auxiliary operating parts, take up a lot of space and increase the load on the vehicle. In this study, the plunger spoiler was optimized with a non-smooth bionic surface for improved

The air distribution system is an essential aircraft system, helping to create a safe, healthy and thermally comfortable cabin environment for large-scale aircraft. This complex pipe network system contains a large number of pipes, valves, elbows, joints and flow devices. The enormous number of components poses a severe challenge to the efficiency, accuracy and convergence of system thermal fluid analysis

Wind load of an external floating-roof tank is analyzed using large eddy simulation (LES). First, the governing equations and a LES solution procedure employing FLUENT software are presented. Subsequently, using two benchmark tank models, the accuracy of LES is examined and the advantages of LES over wind Reynolds-averaged Navier-Stokes (RANS) method in computing the unsteady wind loads and vortex

Owing to the oversimplification of the evaporation model, existing numerical analysis cannot accurately characterize the evaporation characteristics, which has limited its significance for engineering. Therefore, by user-defined programming, a droplet evaporation model in line with the properties of desulfurization wastewater was implemented in numerical simulation. The effects of guiding measures

ABSTRACT After water flooding, there is much residual oil left in the pores. This cannot be easily displaced, but polymer flooding is able to achieve this. The use of viscoelastic solutions such as polymer can enhance the oil recovery, because it can increase the sweep volume by improving the mobility ratio of polymer solution and oil. The use of viscoelastic solutions can also increase the displacement

One of the difficult requirements imposed on high-quality CFD mesh generation has been the ability to evaluate the mesh quality efficiently. Due to the lack of a general and effective evaluating criterion, the current mesh quality evaluation task mainly relies on various quality metrics for the shape of mesh elements, such as angle, radius, edge and contextual information collected by pre-processing

Augmenting the thermal conductivity (TC) of fluids makes them more favorable for thermal applications. In this regard, nanofluids are suggested for achieving improved heat transfer owing to their modified TC. The TC of the base fluid, the volume fraction and mean diameter of particles, and the temperature are the main elements influencing the TC of nanofluids. In this article, two approaches, namely

A novel combination of the ant colony optimization algorithm (ACO)and computational fluid dynamics (CFD) data is proposed for modeling the multiphase chemical reactors. The proposed intelligent model presents a probabilistic computational strategy for predicting various levels of three-dimensional bubble column reactor (BCR) flow. The results prove an enhanced communication between ant colony prediction

How to theoretically describe the process of turbulence formation emains an unsolved problem. A new method is presented in this paper for quantitatively researching the turbulence phase transition based on a dimensionless method and catastrophe theory. Then, the formula of energy spectrum density Ek, with the wave number and time-scale index strictly derived from the folding catastrophe model, can

Hydrological droughts are characterized based on their duration, severity, and magnitude. Among the most critical factors, precipitation, evapotranspiration, and runoff are essential in modeling the droughts. In this study, three indices of drought, i.e., Standardized Precipitation Index (SPI), Standardized Streamflow Index (SSI), and Standardized Precipitation Evapotranspiration Index (SPEI), are

The potential of several predictive models including multiple model-artificial neural network (MM-ANN), multivariate adaptive regression spline (MARS), support vector machine (SVM), multi-gene genetic programming (MGGP), and ‘M5Tree’ were assessed to simulate the pan evaporation in monthly scale (EPm) at two stations (e.g. Ranichauri and Pantnagar) in India. Monthly climatological information were

The longitudinal dispersion coefficient (LDC) plays an important role in modeling the transport of pollutants and sediment in natural rivers. As a result of transportation processes, the concentration of pollutants changes along the river. Various studies have been conducted to provide simple equations for estimating LDC. In this study, machine learning methods, namely support vector regression, Gaussian

The cavitation development process in regulating valve under different inlet pressures is investigated experimentally and numerically in our paper. The influence of inlet pressure Pin on cavitation location, shape, area and intensity is studied in axial and radial directions, and the axial and radial pressure distributions are also analyzed. The cavitation is generally annular in shape radially and

An aerodynamic inverse design method, which is used in compressors, is introduced in this paper. This inverse design method is based on the exact solution of the local Riemann problem on moving blade surfaces. Furthermore, an improved relaxation factor is added to control the induced velocity for reasonable deformation sizes in different cases. The viscous flow analysis and the inverse design are integrated

In this research, a novel method to investigate the transient heat transfer coefficient in a channel is proposed, in which the water flow, itself, is considered both single-phase and two-phase. The experiments were designed to predict the temporal and spatial resolution of the Nusselt number. The inverse technique method is non-intrusive, in which time history of temperature is measured, using some

ABSTRACT The effect of urban form on energy consumption has been the subject of various studies around the world. Having examined the effect of buildings on energy consumption, these studies indicate that the physical form of a city has a notable impact on the amount of energy consumed in its spaces. The present study identified the variables that affected energy consumption in residential buildings

In this study, a numerical simulation is applied to investigate the effective factors on the seepage from the earthen channels. To authenticate the information at hand, some of the earthen channels in the Zayandeh-Rud irrigation network in Iran and Gediz watershed in Turkey were studied. 246 numerical models, including different sections of trapezoidal, rectangular and triangular earthen channels,

Some aerodynamic results about the effect of moving train on the aerodynamics of train-bridge system in crosswinds are introduced using a computational fluid dynamics (CFD) method. In the simulation, a new overset mesh approach is applied to present the motion of trains, and the results are compared with that of the scaled wind tunnel experiment to validate the accuracy of the mesh and algorithm. Besides

A high-speed train will likely experience hazardous driving environments because of the transient effect of complex airflow condition when the train runs on the infrastructure scenario consisting of the tunnel–bridge–tunnel under crosswind. The evolution of aerodynamic loads and flow structure is investigated by numerical simulations. In these simulations, the arrangement of an infrastructural scenario

Pressure drop (Δp) and collection efficiency (η) are used to evaluate the separation performance of the cyclone separator. In this study, we conducted comparative study of cyclone models using response surface methodology (RSM), back propagation neural network (BPNN), and group method of data handling (GMDH) networks to develop optimal predictive cyclone models. Also, we conducted multi-objective optimization

In order to strictly control the solid impurity particles of the pipeline and ensure the cleanliness of the pipeline of the gas supply system, a filter is installed on the pipeline before the inlet of the equipment to ensure the normal operation of the pipeline instrumentation and compressors. Since the flow of the fluid will impact the filter screen, the impact stress of the fluid on the filter screen

The numerical simulation of unsteady cavitation flows is sensitive to the selected models and associated parameters. Consequently, three Reynolds Average Navier-Stokes (RANS) turbulence models and the Zwart cavitation model were selected to assess their performance for the simulation of cloud cavitation on 2D hydrofoils. The experimental cavitation tests from a NACA65012 hydrofoil at different hydrodynamic

Various erosion patterns generated through the cavitating water jet impacts under ambient pressure conditions were investigated in experiments and numerical simulations. A series of normalized stand-off distances ls/do ∈ [2.5 13.5] were studied during the erosion acceleration period. Two ring-like erosion areas were observed for comparatively low ls/do ∈ [2.5 6.5]. To gain insight into the pulse pressure

Oil–water two-phase flow is common in the ocean engineering, petroleum, and chemical industries, among others. In the transportation process, the elbow system – as a paramount component – usually suffers from internal corrosion. In order to investigate the corrosion-prone characteristics of elbow systems, the volume of fluid (VOF) method and the renormalization group (RNG) k-ε model were used to study

Ensuring adequate ventilation during tunnel construction is a critical issue that directly affects construction efficiency. A good ventilation environment can effectively guarantee the construction progress. In this paper, by repeatedly selecting the flow field simulation parameters and continuously summarizing the calculation methods, a reasonable model is selected to simulate the tunnel engineering

The possible changes in precipitation of Syrian due to climate change are projected in this study. The symmetrical uncertainty (SU) and multi-criteria decision-analysis (MCDA) methods are used to identify the best general circulation models (GCMs) for precipitation projections. The effectiveness of four bias correction methods, linear scaling (LS), power transformation (PT), general quantile mapping

ABSTRACT Evaporation, one of the fundamental components of the hydrology cycle, is differently influenced by various meteorological variables in different climatic regions. The accurate prediction of evaporation is essential for multiple water resources engineering applications, particularly in developing countries like Iraq where the meteorological stations are not sustained and operated appropriately

Slurry pipeline transport, which is widely used in dredging, is an important method of solid material transportation. The internal structure information of flows with different shaped particles must be obtained to investigate the effects of different particle shapes on the efficiency and flow characteristics of slurry transport. To solve this problem, a numerical method which couples the computational

ABSTRACT In this study, a numerical model of a partial wellbore is developed by coupling computational fluid dynamics (CFD) with the discrete element method (DEM) in order to simulate the operation of a double-circulation system (DCS) in coalbed methane (CBM) well drilling, which is a novel technique used for cuttings transport. The values of the flow field are computed by a fluid solver and the motions

The natural gas compressibility factor indicates the compression and expansion characteristics of natural gas under different conditions. In this study, a simple second-order polynomial method based on the group method of data handling (GMDH) is presented to determine this critical parameter for different natural gases at different conditions, using corresponding state principles. The accuracy of the

As a method for extracting metals and their compounds, hydrometallurgy has the advantages of high comprehensive metal recovery rate, low environmental pollution, and easier production process. The intensive washing process is a key process in the hydrometallurgical process, and the underflow concentration is a key indicator for measuring the quality of the concentrated washing process. In this paper

ABSTRACT In this work, a numerical and experimental study is performed to evaluate the affecting variables on energy efficiency of a novel regenerative evaporative cooler utilizing dew-point indirect evaporative cooling. For first time, an investigation is experimentally and numerically carried out to study the effects of the channel number on important parameters such as product temperature and humidity