Journal of Fluids Engineering: Recent submissions
Now showing items 1141-1160 of 9024
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Affinity Law Modified to Predict the Pump Head Performance for Different Viscosities Using the Morrison Number
(The American Society of Mechanical Engineers (ASME), 2019)The goal of this study is to provide pump users a simple means to predict a pump's performance change due to changing fluid viscosity. During the initial investigation, it has been demonstrated that pump performance can ... -
Shear Layer Development, Separation, and Stability Over a Low-Reynolds Number Airfoil
(The American Society of Mechanical Engineers (ASME), 2018)The shear layer development for a NACA 0025 airfoil at a low Reynolds number was investigated experimentally and numerically using large eddy simulation (LES). Two angles of attack (AOAs) were considered: 5 deg and 12 deg. ... -
The Mechanism of Size-Based Particle Separation by Dielectrophoresis in the Viscoelastic Flows
(The American Society of Mechanical Engineers (ASME), 2018)Viscoelastic solution is encountered extensively in microfluidics. In this work, the particle movement of the viscoelastic flow in the contraction–expansion channel is demonstrated. The fluid is described by the Oldroyd-B ... -
Investigation on Flow Characteristics of Pump-Turbine Runners With Large Blade Lean
(The American Society of Mechanical Engineers (ASME), 2018)Frequent changes in the operating modes pose significant challenges in the development of a pump-turbine with high efficiency and stability. In this paper, two pump-turbine runners, one with a large positive blade lean and ... -
Unsteady Flow and Pressure Pulsation Characteristics Analysis of Rotating Stall in Centrifugal Pumps Under Off-Design Conditions
(The American Society of Mechanical Engineers (ASME), 2018)Unsteady flow phenomena like rotating stall frequently occur in centrifugal pumps under off-design conditions. Rotating stall could lead to flow instabilities and pressure pulsation, which affect the normal operation of ... -
An Experimental Characterization of the Interaction Between Two Tandem Planar Jets in a Crossflow
(The American Society of Mechanical Engineers (ASME), 2018)This study reports an experimental investigation of two planar jets in a crossflow in a tandem arrangement. Tests were conducted in an open-jet wind tunnel facility using two-dimensional (2D)-particle imaging velocimetry ... -
Numerical Analysis of the Pressure Peak Position Shift With Deadrise Angle in Two-Dimensional Wedge Water Entry
(The American Society of Mechanical Engineers (ASME), 2018)This study deals with the pressure peak position shift with deadrise angle during the initial phase of a two-dimensional (2D) wedge water entry. The finite volume method with volume of fluid (VOF) and dynamic mesh technique ... -
Parametric Study and Optimization of Flow Characteristics of Wire-Nonparallel Plate-Type Electrostatic Air Accelerators
(The American Society of Mechanical Engineers (ASME), 2018)Wire and nonparallel plate electrode-type electrostatic air accelerators have attracted significant interest. The physical process involved in using accelerators is complicated. Moreover, mechanisms are unclear, especially ... -
Numerical Analysis of the Effect of Misaligned Guide Vanes on Improving S-Shaped Characteristics for a Pump-Turbine
(The American Society of Mechanical Engineers (ASME), 2018)The S-shaped characteristic curves in pump-turbines complicate synchronization with the electrical grid and affect system safety. Misaligned guide vanes (MGVs) are one of the most effective solutions to avoid S-shaped ... -
Analytical Upper Limit of Drag Reduction With Polymer Additives in Turbulent Pipe Flow
(The American Society of Mechanical Engineers (ASME), 2018)Flow drag reduction induced by chemical additives, more commonly called drag-reducing agents (DRAs), has been studied for many years, but few studies can manifest the mechanism of this phenomenon. In this paper, a new ... -
A Pioneering Method for Reducing Water Droplet Erosion
(The American Society of Mechanical Engineers (ASME), 2018)Based on computational fluid dynamics and the finite volume method, water droplet erosion in the last stage of an industrial steam turbine was researched and the trajectories of the water droplets were traced by using the ... -
A Study on Slip Characteristics Using Hybrid Particle-Continuum Method
(The American Society of Mechanical Engineers (ASME), 2018)An effective boundary potential has been proposed to solve nonperiodic boundary condition (NPBC) of hybrid method. The optimized hybrid method is applied to investigate the influences of the channel height and solid–liquid ... -
A Hybrid Eulerian–Eulerian Discrete-Phase Model of Turbulent Bubbly Flow
(The American Society of Mechanical Engineers (ASME), 2018)The Eulerian–Eulerian two-fluid model (EE) is a powerful general model for multiphase flow computations. However, one limitation of the EE model is that it has no ability to estimate the local bubble sizes by itself. In ... -
Francis-Type Reversible Turbine Field Investigation During Fast Closure of Wicket Gates
(The American Society of Mechanical Engineers (ASME), 2018)Flexible electricity demand and variability of the electricity produced by wind turbines and photovoltaic affect the stable operations of power grids. Pump-turbines are used to stabilize the power grid by maintaining a ... -
A Unified Energy Feature of Vortex Rings for Identifying the Pinch-Off Mechanism
(The American Society of Mechanical Engineers (ASME), 2018)Owing to the limiting effect of energy, vortex rings cannot grow indefinitely and thus pinch off. In this paper, experiments on the vortex rings generated using a piston-cylinder apparatus are conducted so as to investigate ... -
Laminar to Turbulent Buoyant Vortex Ring Regime in Terms of Reynolds Number, Bond Number, and Weber Number
(The American Society of Mechanical Engineers (ASME), 2018)When buoyant vortex rings form, azimuthal disturbances occur on their surface. When the magnitude of the disturbance is sufficiently high, the ring will become turbulent. This paper establishes conditions for categorization ... -
Three-Dimensional Design Simulations of a High-Energy Density Reshock Experiment at the National Ignition Facility
(The American Society of Mechanical Engineers (ASME), 2018)We present simulations of a new experimental platform at the National Ignition Facility (NIF) for studying the hydrodynamic instability growth of a high-energy density (HED) fluid interface that undergoes multiple shocks, ... -
Unsteady Behaviors of Steam Flow in a Control Valve With T-Junction Discharge Under the Choked Condition: Detached Eddy Simulation and Proper Orthogonal Decomposition
(The American Society of Mechanical Engineers (ASME), 2018)Due to the practical space limitation, the control valve in industrial utilities is usually immediately followed by a short flow passage, which would introduce considerable complexity into highly unsteady flow behaviors, ... -
Hydraulic Stability Analysis of a Large Prototype Francis Turbine Based on Field Test
(The American Society of Mechanical Engineers (ASME), 2018)Long time field tests of a 200 MW prototype Francis turbine over its full range of operation were conducted. From the experimental data, the time domain and frequency domain characteristics of the pressure fluctuations in ... -
Fully-Developed Flow in Semicircular and Isosceles Triangular Ducts With Nonuniform Slip
(The American Society of Mechanical Engineers (ASME), 2018)A modified Ritz method for solving nonuniform slip flow in a duct is applied to the semicircular duct and the isosceles triangular duct. These ducts are important in microfluidics. Detailed flow fields and Poiseuille numbers ...