scholarly journals Estimation on Pressure and Velocity Parameter in the Fuel Handling Pneumatic Design of RDE

2020 ◽  
Vol 1493 ◽  
pp. 012002
Author(s):  
Sukmanto Dibyo ◽  
Topan Setiadipura ◽  
Marliyadi Pancoko
Keyword(s):  
Velocity Parameter

scholarly journals Nanofluid flow containing carbon nanotubes with quartic autocatalytic chemical reaction and Thompson and Troian slip at the boundary

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Muhammad Ramzan ◽  
Jae Dong Chung ◽  
Seifedine Kadry ◽  
Yu-Ming Chu ◽  
Muhammad Akhtar
Keyword(s):  
Mathematical Model ◽  
Carbon Nanotubes ◽  
Drag Force ◽  
Chemical Reaction ◽  
Slip Velocity ◽  
Volume Fraction ◽  
Surface Drag ◽  
Nanofluid Flow ◽  
Velocity Parameter ◽  
The Impact

Abstract A mathematical model is envisioned to discourse the impact of Thompson and Troian slip boundary in the carbon nanotubes suspended nanofluid flow near a stagnation point along an expanding/contracting surface. The water is considered as a base fluid and both types of carbon nanotubes i.e., single-wall (SWCNTs) and multi-wall (MWCNTs) are considered. The flow is taken in a Dacry-Forchheimer porous media amalgamated with quartic autocatalysis chemical reaction. Additional impacts added to the novelty of the mathematical model are the heat generation/absorption and buoyancy effect. The dimensionless variables led the envisaged mathematical model to a physical problem. The numerical solution is then found by engaging MATLAB built-in bvp4c function for non-dimensional velocity, temperature, and homogeneous-heterogeneous reactions. The validation of the proposed mathematical model is ascertained by comparing it with a published article in limiting case. An excellent consensus is accomplished in this regard. The behavior of numerous dimensionless flow variables including solid volume fraction, inertia coefficient, velocity ratio parameter, porosity parameter, slip velocity parameter, magnetic parameter, Schmidt number, and strength of homogeneous/heterogeneous reaction parameters are portrayed via graphical illustrations. Computational iterations for surface drag force are tabulated to analyze the impacts at the stretched surface. It is witnessed that the slip velocity parameter enhances the fluid stream velocity and diminishes the surface drag force. Furthermore, the concentration of the nanofluid flow is augmented for higher estimates of quartic autocatalysis chemical.

scholarly journals Near-occlusion is difficult to diagnose with common carotid ultrasound methods

2021 ◽  
Vol 63 (5) ◽  
pp. 721-730
Author(s):  
Elias Johansson ◽  
Davide Vanoli ◽  
Isa Bråten-Johansson ◽  
Lucy Law ◽  
Richard I Aviv ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Sensitivity And Specificity ◽  
Low Flow ◽  
Reference Standard ◽  
Carotid Ultrasound ◽  
Ultrasound Method ◽  
Velocity Parameter ◽  
Near Occlusion

Abstract Purpose To assess the sensitivity and specificity of common carotid ultrasound method for carotid near-occlusion diagnosis. Methods Five hundred forty-eight patients examined with both ultrasound and CTA within 30 days of each other were analyzed. CTA graded by near-occlusion experts was used as reference standard. Low flow velocity, unusual findings, and commonly used flow velocity parameters were analyzed. Results One hundred three near-occlusions, 272 conventional ≥50% stenosis, 162 <50% stenosis, and 11 occlusions were included. Carotid ultrasound was 22% (95%CI 14–30%; 23/103) sensitive and 99% (95%CI 99–100%; 442/445) specific for near-occlusion diagnosis. Near-occlusions overlooked on ultrasound were found misdiagnosed as occlusions (n = 13, 13%), conventional ≥50% stenosis (n = 65, 63%) and < 50% stenosis (n = 2, 2%). No velocity parameter or combination of parameters could identify the 65 near-occlusions mistaken for conventional ≥50% stenoses with >75% sensitivity and specificity. Conclusion Near-occlusion is difficult to diagnose with commonly used carotid ultrasound methods. Improved carotid ultrasound methods are needed if ultrasound is to retain its position as sole preoperative modality.

scholarly journals Effect of magnetized variable thermal conductivity on flow and heat transfer characteristics of unsteady Williamson fluid

2020 ◽  
Vol 9 (1) ◽  
pp. 338-351
Author(s):  
Usha Shankar ◽  
N. B. Naduvinamani ◽  
Hussain Basha
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Fluid Flow ◽  
Velocity Profile ◽  
Variable Thermal Conductivity ◽  
Flow Index ◽  
Williamson Fluid ◽  
Flow Equations ◽  
Velocity Parameter ◽  
Squeezed Flow

AbstractA two-dimensional mathematical model of magnetized unsteady incompressible Williamson fluid flow over a sensor surface with variable thermal conductivity and exterior squeezing with viscous dissipation effect is investigated, numerically. Present flow model is developed based on the considered flow geometry. Effect of Lorentz forces on flow behaviour is described in terms of magnetic field and which is accounted in momentum equation. Influence of variable thermal conductivity on heat transfer is considered in the energy equation. Present investigated problem gives the highly complicated nonlinear, unsteady governing flow equations and which are coupled in nature. Owing to the failure of analytical/direct techniques, the considered physical problem is solved by using Runge-Kutta scheme (RK-4) via similarity transformations approach. Graphs and tables are presented to describe the physical behaviour of various control parameters on flow phenomenon. Temperature boundary layer thickens for the amplifying value of Weissenberg parameter and permeable velocity parameter. Velocity profile decreased for the increasing squeezed flow index and permeable velocity parameter. Increasing magnetic number increases the velocity profile. Magnifying squeezed flow index magnifies the magnitude of Nusselt number. Also, RK-4 efficiently solves the highly complicated nonlinear complex equations that are arising in the fluid flow problems. The present results in this article are significantly matching with the published results in the literature.

The interaction of deep-water gravity waves and an annular current: linear theory

1993 ◽  
Vol 248 ◽  
pp. 153-172 ◽  
Author(s):  
Marius Gerber
Keyword(s):  
Linear Theory ◽  
Gravity Waves ◽  
Deep Water ◽  
Large Scale ◽  
Ray Theory ◽  
Velocity Parameter ◽  
Dimensional Parameters ◽  
The Waves ◽  
Angle Parameter

The interaction of linear, steady, axisymmetric deep-water gravity waves with preexisting large-scale annular currents has been investigated. Waves originating inside the annulus as well as waves approaching the annulus from the outside were studied. Exact linear ray solutions were obtained and involve two non-dimensional parameters, a radius-angle parameter and a velocity parameter. For opposing currents the linear solutions also allow the derivation of radii at which the waves are blocked, reflected at a linear caustic or stopped by the current. Various examples of rays interacting with an annular current are presented to illustrate aspects of the solutions obtained. In particular, the behaviour of the ray solutions at blocking, reflection and stopping is investigated. Linear ray theory is shown to fail at caustics and caustic solutions are briefly discussed.

The ionisation curve of an average α particle

1928 ◽  
Vol 24 (1) ◽  
pp. 139-149 ◽  
Author(s):  
N. Feather ◽  
R. R. Nimmo
Keyword(s):  
Light Scattering ◽  
Experimental Results ◽  
Particle Track ◽  
Expansion Chamber ◽  
Velocity Parameter ◽  
Controlled Illumination ◽  
Α Particles

Photographs have been taken under controlled illumination of the tracks of α particles in a cloud expansion chamber and a calibration of the photographic plates employed has been carried out. Systematic photometry of the track images has made possible the calculation of the variation of the light scattering power of an α particle track over the last two centimetres of its length in standard air, and the variation of this quantity has been identified with the variation of ionisation along the track.Photographs of tracks in air, helium and hydrogen have been examined. In these three gases the maximum ionising efficiency of the α particle occurs when it possesses the velocity respectively appropriate to the distances 3·0, 2·55 and 2·25 mms. from the end of its path in standard air. This common velocity parameter has been employed throughout the discussions which are appended to the experimental results.

scholarly journals A New Parametric Tropical Cyclone Tangential Wind Profile Model

2013 ◽  
Vol 141 (6) ◽  
pp. 1884-1909 ◽  
Author(s):  
Vincent T. Wood ◽  
Luther W. White ◽  
Hugh E. Willoughby ◽  
David P. Jorgensen
Keyword(s):  
Tropical Cyclone ◽  
Wind Profile ◽  
Tangential Velocity ◽  
Pressure Rise ◽  
Central Pressure ◽  
Velocity Parameter ◽  
Profile Model ◽  
Tangential Wind ◽  
Multiple Maxima ◽  
Wind Profiles

Abstract A new parametric tropical cyclone (TC) wind profile model is presented for depicting representative surface pressure profiles corresponding to multiple-maxima wind profiles that exhibit single-, dual-, and triple-maximum concentric-eyewall wind peaks associated with the primary (inner), secondary (first outer), and tertiary (second outer) complete rings of enhanced radar reflectivity. One profile employs five key parameters: tangential velocity maximum, radius of the maximum, and three different shape velocity parameters related to the shape of the profile. After tailoring the model for TC applications, a gradient wind is computed from a cyclostrophic wind formulated in terms of the cyclostrophic Rossby number. A pressure, via cyclostrophic balance, was partitioned into separate pressure components that corresponded to multiple-maxima cyclostrophic wind profiles in order to quantitatively evaluate the significant fluctuations in central pressure deficits. The model TC intensity in terms of varying growth, size, and decay velocity profiles was analyzed in relation to changing each of five key parameters. Analytical results show that the first shape velocity parameter, changing a sharply to broadly peaked wind profile, increases the TC intensity and size by producing the corresponding central pressure fall. An increase (decrease) in the second (third) shape velocity parameter yields the pressure rise (fall) by decreasing (increasing) the inner (outer) wind profile inside (outside) the radius of the maximum. When a single-maximum tangential wind profile evolves to multiple-maxima tangential wind profiles during an eye replacement cycle, the pressure falls and rises are sensitively fluctuated.

A Non-Dimensional Weight-Velocity Parameter for Estimating Drag Force and Net Deformation of Gravity Fish Cages

2005 ◽  
Author(s):  
Kyrre Vikestad ◽  
Egil Lien
Keyword(s):  
Computer Simulations ◽  
Drag Force ◽  
Current Velocity ◽  
Mooring System ◽  
Equivalent Weight ◽  
Velocity Parameter ◽  
Gravity Forces ◽  
Net Cage ◽  
Fish Cages ◽  
Weight Velocity

Most floating fish cages consist of a floating cage collar, mooring system, and net cage hanging freely down from the floater. Any current moving through the net will deform the net. This deformation depends on the current velocity, the nets ability to attract forces, and the gravity forces from weights at the lower end of the net. The forces on the net will vary with the deformation. This paper shows that for this kind of cage, a reduced velocity Vred = U·(ρ/2G)1/2, where G is the equivalent weight per area of the net, will be sufficient to estimate the drag force and deformation of the net. The present work is analytical, combined with computer simulations. The reduced velocity parameter could be used to determine the needed bottom weights. The quick estimation of the drag force on the net could be used as an input to mooring design.

scholarly journals Construction of Solitary Two-Wave Solutions for a New Two-Mode Version of the Zakharov-Kuznetsov Equation

Mathematics ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 1127 ◽  
Author(s):  
Imad Jaradat ◽  
Marwan Alquran
Keyword(s):  
Phase Velocity ◽  
Exact Solutions ◽  
Three Dimensional ◽  
Soliton Solutions ◽  
Two Dimensional ◽  
Velocity Parameter ◽  
Interaction Dynamics ◽  
Wave Solutions ◽  
Proposed Model ◽  
Singular Soliton

A new two-mode version of the generalized Zakharov-Kuznetsov equation is derived using Korsunsky’s method. This dynamical model describes the propagation of two-wave solitons moving simultaneously in the same direction with mutual interaction that depends on an embedded phase-velocity parameter. Three different methods are used to obtain exact bell-shaped soliton solutions and singular soliton solutions to the proposed model. Two-dimensional and three-dimensional plots are also provided to illustrate the interaction dynamics of the obtained two-wave exact solutions upon increasing the phase-velocity parameter.

Sign in / Sign up

Export Citation Format

Share Document