Effects Of Coriolis Forces Research Articles

Computational modeling of axial rotation for the evolution of temperature in horizontal toroidal cans under pasteurization conditions

Axial rotation mechanism has been widely used during thermal processing of liquid containing cans. Besides this can geometry modification might be an innovative approach to increase heat transfer rates. Therefore, the objective of this study was to determine temperature distribution and effect of rotation rate in axially rotating toroidal cans. For this purpose, experimental and numerical modeling studies were carried out. In the experimental studies, toroidal cans including distilled water were processed in hot water, and temperature data were used for computational model validation and mesh independency. Then, the second set of simulations were conducted to determine the rotational effects on temperature evolution. Effects of gravitational buoyancy, centrifugal and Coriolis forces were determined, and Coriolis forces increased up to 4 times with increased rotation rates (20–160 rpm). With this aspect, process time for 70 °C increase was reduced by ≈40 and 33.3% at 80 and 160 rpm compared to conventinal cylindrical cans. This study is an introduction to modify can geometry and process parameters to reduce quality losses and decrease energy use. However, industrial practice has still significant challenge for manufacturing and using in the process line.

Heat transfer in an impingement cooling channel under isothermal boundaries at high rotation numbers

The jet impingement cooling technology is usually applied in the turbine blade leading edge which suffers the highest heat flux and needs priority protection. Therefore, heat transfer performances in a rotating impingement cooling channel under an isothermal boundary are experimentally studied. Both the jet-to-target surface spacing and the jet-to-jet spacing are 3 times the jet hole diameter. The effects of Coriolis force and buoyancy force on heat transfer are focused. And the maximum rotation number and buoyancy number reaches 1.63 and 8.06, respectively. The Reynolds number varies from 7119 to 21,358. Besides, numerical simulations are conducted to predict the flow field. The results show that the heat transfer in the impingement channel is determined by the radial mass-flowrate distribution of supply channel in both static and rotating states. Moreover, the rotation enhances the heat transfer at both ends but decreases the heat transfer in the middle-radius due to the stagnant zone induced by Coriolis force in the supply channel, resulting in large thermal stress on the target surface. However, the heat transfer is insensitive to the rotational effects when the rotation number exceeds 0.42. There is a critical rotation number for each location, before which the effect of buoyancy force could be neglected. Once the rotation number is greater than this value, the effect of buoyancy force increases with the wall-to-fluid temperature ratio.

A control-oriented large eddy simulation of wind turbine wake considering effects of Coriolis force and time-varying wind conditions

A control-oriented large eddy simulation (LES) code is developed to predict wind turbine wake and is validated by laboratory-scale and utility-scale wind turbines. Firstly, the wind turbine control algorithms including torque, pitch and yaw controls are implemented in LES with Actuator Line Model (ALM). Two sets of numerical simulations under uniform inflow with time-varying wind speeds and wind directions are performed. The simulated thrust and torque forces agree well with those calculated by the aeroelastic code, FAST. The predicted mean velocity and turbulence intensity in the wake of a laboratory-scale wind turbine show favorable agreement with those measured in wind tunnel experiments. The blade rotation induced dynamic effects on wake flows and rotor loading are well reproduced by ALM. Finally, numerical simulations for a utility-scale wind turbine are conducted, in which the ambient flow filed with time-varying wind speeds and wind directions are generated based on the wind condition measured by the Met-mast and the Coriolis force effect is incorporated as well. The predicted time series of control signals and power production agree well with the wind turbine SCADA data and the predicted mean wind speed in the wake region show favorable agreement with those measured by Doppler scanning LiDAR.

Direct numerical simulation of turbulent elliptical pipe flow under system rotation about the major axis

The effect of Coriolis forces on the turbulent flow in an elliptical pipe subjected to spanwise rotation has been studied using direct numerical simulations (DNS). In response to the system rotation, large-scale secondary flows appear in the cross-stream plane as a pair of counter-rotating vortices, which significantly impact the turbulence statistics and structures of the flow. The characteristics of the turbulence field is investigated in both physical and spectral spaces through analyses of the first- and second-order statistical moments, as well as the budget balance of the Reynolds stress transport equation and coherent flow structures.

Turbidity currents at polar latitudes: A case study of NP-28 channel in the Amundsen Basin, Arctic Ocean

Turbidity currents are fundamental marine sedimentary processes that deliver sediments from continental margins to deep ocean basins. They develop and maintain deep-sea channels that act as principal conduits for this sediment delivery. While turbidity current channels are frequently considered as analogous to river channel systems, there are distinct differences in the mechanisms that govern their formation. This is particularly true at high-latitudes, where glacial margin processes and Coriolis effects have direct consequences on the characteristics of channel-forming turbidity currents. Understanding the latitudinal controls that influence the structure of these channels is thus a key objective of this study.The geomorphology of the glacial-fed NP-28 Channel in the Amundsen Basin of the Arctic Ocean, the highest-latitude deep-sea channel on Earth, is assessed. Compilation of available bathymetry shows that the channel follows a low-gradient, low-sinuosity path roughly paralleling the base of Lomonosov Ridge. The channel has a broad cross-section comparable to other glacially-fed and tributary-fed deep-ocean channel systems. High-resolution subbottom profiles reveal intrachannel terraces and an incised channel thalweg that were likely formed through erosion by traction-dominated currents; stratified levees and sediment waves were likely deposited by overbank flows. Coriolis deflection of channel-filling currents is evident from consistent levee asymmetry along the entire channel path. Within the channel, the channel floor geometry suggests local dominance of both Coriolis and centrifugal forces at the base of the channel; the latter in particular where the channel is deflected by external bedrock. Overall, channel morphology is largely consistent with existing models of Coriolis force effects on turbidity currents at high latitudes. This influence of Coriolis force, in addition to the presumed glacial style of the sediment input and bedrock interaction with the channel path, are considered the major factors that affected channel morphology.

Effects of Coriolis force on the nonlinear interactions of acoustic-gravity waves in the atmosphere

The nonlinear theory of acoustic-gravity waves (AGWs) in the atmosphere is revisited with the effects of the Coriolis force. Previous theory in the literature (Mendonça and Stenflo, 2015) is advanced. Starting from a set of fluid equations modified by the Coriolis force, a general linear dispersion relation is derived which manifests the coupling of the high-frequency acoustic-gravity waves (AGWs) and the low-frequency internal gravity waves (IGWs). The frequency of IGWs is enhanced by the Earth’s angular velocity. The latter also significantly modifies the nonlinear coupling of AGWs and IGWs whose evolutions are described by the Zakharov approach as well as the Wigner–Moyal formalism. The consequences of AGWs and the two equivalent evolution equations modified by the Coriolis force are briefly discussed.

Nonlinear forced vibration of rotating composite laminated cylindrical shells under hygrothermal environment

Abstract This work aims to study nonlinear vibration of rotating composite laminated cylindrical shells under hygrothermal environment and radial harmonic excitation. Based on Love’s nonlinear shell theory, and considering the effects of rotation-induced initial hoop tension, centrifugal and Coriolis forces, the nonlinear partial differential equations of the shells are derived by Hamilton’s principle, in which the constitutive relation and material properties of the shells are both hygrothermal-dependent. Then, the Galerkin approach is applied to discrete the nonlinear partial differential equations, and the multiple scales method is adopted to obtain an analytical solution on the dynamic response of the nonlinear shells under primary resonances of forward and backward traveling wave, respectively. The stability of the solution is determined by using the Routh–Hurwitz criterion. Some interesting results on amplitude–frequency relations and nonlinear dynamic responses of the shells are proposed. Special attention is given to the combined effects of temperature and moisture concentration on nonlinear resonance behavior of the shells.

Vibration characteristics of rotating functionally graded circular cylindrical shell with variable thickness under thermal environment

This paper deals with the vibration characteristics of rotating functionally graded circular cylindrical shells (FG-CS). The thickness of the shell varies linearly along the longitudinal direction. The material properties are graded continuously with a power law (P-FGM) in the radial direction and depend on the temperature. The system of motion equation is established by using the first-order shear deformation theory (FSDT) and Hamilton's principle. The model considers the effects of centrifugal forces, Coriolis forces, and initial hoop tension due to rotation. The natural frequencies of the shells with various boundary conditions are obtained by Galerkin's method. Several competition examples validated the accuracy of the present model. Some numerical studies are then conducted to identify the effects of rotational speed, material properties, geometrical parameters, and boundary conditions (BCs) on the vibration response of rotating FG-CS in detail.

Effect of TD viscosity and Coriolis force on thermohaline convection of ferrofluid in Darcy porous matrix: A Galerkin numerical technique

The effect of TD viscosity (Temperature Dependent viscosity) and Coriolis force in horizontal ferromagnetic fluid layer with Darcy porous matrix is investigated theoretically. This fluid layer is heated from below and it is salted from above. The non-linear behavior is omitted by use of a linear stability theory. The normal mode technique is taken to account to investigate the convective system with free-free boundaries. To investigate the entire system the exact solution is obtained. The stationary instability is obtained. But, oscillatory instability can not occur in the study. The critical thermal magnetic Rayleigh number N S C is calculated for sufficient large values of M 1. In the analysis, we have attempted to analyze T a , V and D a on the system in many situations.

The effects of Coriolis force and radial stretch on the convective instability characteristics of the Bödewadt flow

The Bödewadt boundary-layer flow is induced by the rotation of a viscous fluid rotating with a constant angular velocity over a stationary disk. In this paper, the Bödewadt boundary-layer flow has been studied in the presence of the Coriolis force to observe the effect of radial stretch of the lower disk on the flow. For the first time in the literature, a numerical investigation of the effects of both stretching mechanism and the Coriolis force on the flow behaviour and on the convective instability characteristics of the above flow has been carried out. In this paper, the Kármán similarity transformations have been considered in order to convert the system of PDEs representing the momentum equations of the flow into a system of highly non-linear coupled ODEs and solved numerically to obtain the velocity profiles of the Bödewadt flow. Then, a convective instability analysis has been performed by using the Chebyshev collocation method in order to obtain the neutral curves. From the neutral curves it is observed that radial stretch has a globally stabilising effect on both the inviscid Type-I and the viscous Type-II instability modes. This underlying physical phenomena has been verified by performing an energy analysis of the flow. The results obtained excellently supports the previous works and will be prominently treated as a benchmark for our future studies.

Insight into the dynamics of fluid conveying tiny particles over a rotating surface subject to Cattaneo–Christov heat transfer, Coriolis force, and Arrhenius activation energy

This article addressees the dynamics of fluid conveying tinny particles and Coriolis force effects on transient rotational flow toward a continuously stretching sheet. Tiny particles are considered due to their unusual characteristics like extraordinary thermal conductivity, which are significant in advanced nanotechnology, heat exchangers, material sciences, and electronics. The main objective of this comprehensive study is the enhancement of heat transportation. The governing equations in three dimensional form are transmuted in to dimensionless two-dimensional form with implementation of suitable scaling transformations. The variational finite element procedure is harnessed and coded in Matlab script to obtain numerical solution of the coupled non-linear partial differential problem. It is observed that higher inputs of the parameters for magnetic force and rotational fluid cause to slow the primary as well as secondary velocities, but the thermophoresis and Brownian motion raise the temperature. However, thermal relaxation parameter reduces the nanofluid temperature. The velocities for viscosity constant case are faster than that for the variable viscosity, but temperature and species concentration depict opposite behavior.

Coriolis Force Effect on Suppression of Neo-Classical Tearing Mode Triggered Explosive Burst in Reversed Magnetic Shear Tokamak PlasmasSupported by the National Natural Science Foundation of China (Grant Nos. 11925501, 11875099, and 11575158), the Liaoning Revitalization Talents Program (Grant No. XLYC1802009), and the China Scholarship Council (Grant No. 201806060036).

We numerically investigate the Coriolis force effect on the suppression of an explosive burst, triggered by the neo-classical tearing mode, in reversed magnetic shear configuration tokamak plasmas, using a reduced magnetohydrodynamic model, including bootstrap current. Previous works have shown that applying differential poloidal rotation, with rotation shear located near the outer rational surface, is an effective way to suppress an explosive burst. In comparison with cases where there is no Coriolis force, the amplitude of differential poloidal rotation required to effectively suppress the explosive burst is clearly reduced once the effect of Coriolis force is taken into consideration. Moreover, the effective radial region of the rotation shear location is broadened in cases where the Coriolis force effect is present. Applying rotation with shear located between the radial positions of q min and the outer rational surface always serves to effectively suppress explosive bursts, which we anticipate will reduce operational difficulties in controlling explosive bursts, and will consequently prevent plasma disruption in tokamak experiments.

Green's function and finite element formulations for the dynamics of pipeline conveying fluid

ABSTRACT Pipeline damage due to internal flow induced vibration is known to pose challenging problems in oil and gas industry. To reduce these problems, it is necessary to understand the vibration characteristics of the pipeline conveying fluid. The Winkler foundation is reported to have a stabilising effect to the pipeline structure in the literature. Therefore, in this study, dynamic analysis of pipeline conveying fluid mounted on the Winkler foundation is performed to obtain the force response of the pipeline. The partial differential equation of the pipeline conveying fluid subjected to several boundary conditions is solved numerically and analytically by using the finite element and Green's function method. The results of both methods are compared and validated against other numerical schemes and existing reported analytical data. The results indicate that Green's function is more accurate than finite element method in determining the forced response of the pipeline at a higher fluid velocity for simply supported and fixed supported pipeline. The findings in the present study provide the physical insight of the Coriolis force and Winkler foundation stiffness effect to the pipeline conveying fluid.

Hydromagnetic boundary layer flow with heat transfer past a rotating disc embedded in a porous medium

AbstractIn this study, the effect of Coriolis force along with the Darcy parameter has been analyzed on time‐dependent forced convective boundary layer flow of conducting fluids over a rotating disc embedded in a porous medium. The modeled system is solved by power series approximations in the Mathematica environment shooted values. The significant impact of the rheological properties, such as Darcy parameter and Prandtl number , of water, hydrocarbon, and kerosene‐based conducting fluids for the deviation of parameter (Karman) has been noted and then analyzed qualitatively and quantitatively with graphs and tables.

Effect of Coriolis Force on Vibration of Annulus Pipe

Annulus pipe conveying fluids have many practical applications, such as hydraulic control lines and aircraft fuel lines. In some applications, these tubes are exposed to high speeds. Normally, this leads to a vibration effect which may be of a catastrophic nature. The phenomenon is not only driven by the centrifugal forces, but an important role is played also by the Coriolis forces. Many theoretical approaches exist for a simple configuration or a complex three-dimensional configuration. Finite element models are tested. This paper provides a numerical technique for solving the dynamics of annulus pipe conveying fluid by means of the mono-dimensional Finite Element Method (FEM). In particular, this paper presents a numerical solution to the equations governing a fluid conveying pipeline segment, where a Coriolis force effect is taken into consideration both for fix and hinge constraint.

Nighttime meridional neutral wind responses to SAPS simulated by the TIEGCM: a universal time effect

The present work uses the Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM), under geomagnetically disturbed conditions that are closely related to the southward interplanetary magnetic field (IMF), to investigate how the nighttime poleward wind (30°–50° magnetic latitude and 19–22 magnetic local time) responds to subauroral polarization streams (SAPS) that commence at different universal times (UTs). The SAPS effects on the poleward winds show a remarkable UT variation, with weaker magnitudes at 00 and 12 UT than at 06 and 18 UT. The strongest poleward wind emerges when SAPS commence at 06 UT, and the weakest poleward wind develops when SAPS occur at 00 UT. A diagnostic analysis of model results shows that the pressure gradient is more prominent for the developing of the poleward wind at 00 and 12 UT. Meanwhile, the effect of ion drag is important in the modulation of the poleward wind velocity at 06 and 18 UT. This is caused by the misalignment of the geomagnetic and geographic coordinate systems, resulting in a large component of ion drag in the geographically northward (southward) direction due to channel orientation of the SAPS at 06 and 18 UT (00 and 12 UT). The Coriolis force effect induced by westward winds maximizes (minimizes) when SAPS commence at 12 UT (00 UT). The centrifugal force due to the accelerated westward winds shows similar UT variations as the Coriolis force, but with an opposite effect.

Free vibration analysis of rotating pre-twisted ceramic matrix carbon nanotubes reinforced blades

A novel dynamic model for rotating pre-twisted carbon nanotubes reinforced composite (CNTRC) blades with elastic boundary constraints is established based on the first-order shear deformation theory (FSDT). The effects of Coriolis and centrifugal forces are considered in the formulation. Based on the Euler-Lagrange equations, the natural frequencies and vibration modes of a rotating pre-twisted blade are obtained. The model’s accuracy is verified by comparing it with the results in the literature and Ansys. The influence of distributions of CNTs, pre-twist angle, rotation speed, and stagger angle on the vibration of the ceramic matrix CNTRC blade is studied in detail.

Coriolis-induced liquid breakup and spray evolution in a rotary slinger atomizer: Experiments and analysis

Understanding the physics of primary liquid breakup process and its correlation with the evolution of spray characteristics in a rotary slinger atomizer is the goal of the present research. Experiments were conducted in a high-speed slinger test rig that houses a static liquid delivery manifold to uniformly supply the liquid to the rotating slinger disc that contains a single row of orifices carved on its peripheral surface for liquid injection.The atomizer was operated for a wide range of conditions by varying the rotational speed and liquid feed rate. The liquid breakup structure at the exit of the slinger orifices was visualized using front light illumination technique, while the droplet size was measured at different radial stations away from the slinger surface by application of the Interferometric Laser Imaging for Droplet Sizing (ILIDS) technique. The visualization images highlighted strong influence of Coriolis force as the liquid tends to accumulate on one side of the channel (that is opposite to the rotational direction) for all cases. It was observed that while the liquid thickness is smaller for higher rotational speed, it does not vary much with liquid feed rate at the same speed and, instead, in such case the span of the liquid is wider. A theoretical analysis was developed to describe the in-channel liquid behaviour that accounts for the effect of Coriolis and surface tension forces. Interestingly, the theory could explain the above observations. The differences in the predictions in comparison to the analysis by Dahm et al. (2006a) was attributed to the assumption of annular film flow in the latter. The liquid breakup mode (stream, sheet or transition mode) could be described by Coriolis Bond number (Bo) that refers to the ratio of Coriolis to surface tension forces and proportional to the spread parameter (span to thickness ratio), while the liquid breakup regimes were identified on a Bo−q plot, where q is the liquid to air momentum flux ratio. The variation of characteristic droplet sizes with both rotational speed and feed rate were examined, and again some interesting trends are identified. The correlation between liquid breakup mode/regime with the measured droplet size was established using the above non-dimensional numbers.

Force control of upper limb exoskeleton to support user movement

The dynamics analysis and control of the upper limb exoskeleton for supporting user movement is done by using the force feedforward control model. Based on a novel combination of Proportional Derivative (PD) force feedforward and Proportional Integral (PI) feedback control model [1], this paper proposes a method to assist the user’s movement for a three degree of freedom exoskeleton structure. When the user exerts force at the handle, the force is measured by a force sensor placed at the handle. These sensed forces are applied to command the actuators to support the human movement and reduce the disturbance effects of the device. This technique is well established approach in haptics for reducing the effects of inertia, damping, friction, centrifugal and Coriolis forces and gravity of haptic device [2]. Simulation result shows the torque controlled by robot to assist human for a desired loading motion.

Effect of Rotation Number on Heat Transfer Characteristics of a Row of Impinging Jets in Confined Channel

Jet impingement has been applied for internal cooling in gas turbine blades. In this study, heat transfer characteristics of impinging jets from a row of circular orifices were investigated inside a flow channel with rotations. The Reynolds number (Re) based on the jet mean velocity was fixed at 6,700. Whereas, the rotation number (Ro) of a channel was varied from 0 to 0.0099. The jet-to-impingement distance ratio (L/Dj) and jet pitch ratio (P/Dj) were respective 2 and 4, Dj is a jet diameter of 5 mm. The thermochromic liquid crystals (TLCs) technique was used to measure the heat transfer coefficient distributions on an impingement surface. The results show that heat transfer enhancement on a jet impingement surface depended on the effects of crossflow and Coriolis force. The local Nusselt number at X/Dj?20 on the leading side (LS) was higher than on the trailing side (TS) while heat transfer on the LS at 20?X/Dj?40 gained the lowest, compared to on the TS. The average Nusselt number ratios ( ) on the TS at Ro = 0.0049 gave higher than on the LS of around 2.17%. On the other hand, the on the TS at Ro = 0.0099 was less than the LS of about 0.08%.