scholarly journals Analytical and Numerical Solutions for the Thermal Problem in a Friction Clutch System

Computation ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 122
Author(s):  
Laith A. Sabri ◽  
Katarzyna Topczewska ◽  
Muhsin Jaber Jweeg ◽  
Oday I. Abdullah ◽  
Azher M. Abed
Keyword(s):  
Numerical Solution ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Numerical Results ◽  
Three Dimensional Model ◽  
Thermal Problem ◽  
Friction Clutch ◽  
Dry Conditions ◽  
The Difference ◽  
Element Technique

The dry friction clutch is an important part in vehicles, which has more than one function, but the most important function is to connect and disconnect the engine (driving part) with driven parts. This work presents a developed numerical solution applying a finite element technique in order to obtain results with high precision. A new three-dimensional model of a single-disc clutch operating in dry conditions was built from scratch. As the new model represents the real friction clutch including all details, the complexity in the geometry of the clutch is considered one of the difficulties that the researchers faced using the numerical solution. The thermal behaviour of the friction clutch during the slip phase was studied. Meanwhile, in the second part of this work, the transient thermal equations were derived from scratch to find the analytical solution for the thermal problem of a clutch disc in order to verify the numerical results. It was found, after comparison of the numerical results with analytical results, that the results of the numerical model are very accurate and the difference between them does not exceed 1%.

Numerical and Experimental Analysis of 3D Micro-Corrugated Wing in Gliding Flight

2021 ◽  
Author(s):  
Nasim Chitsaz ◽  
Kamran Siddiqui ◽  
Romeo Marian ◽  
Javaan S. Chahl
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Aerodynamic Performance ◽  
Numerical Results ◽  
Three Dimensional Model ◽  
Wing Model ◽  
Computational Fluid Dynamics Analysis ◽  
Gliding Flight ◽  
Flat Profile

Abstract In this study, computational fluid dynamics analysis was performed on a three-dimensional model of a Libellulidae wing to determine aerodynamic performance in gliding flight. The wing is comprised of various corrugated features alongside the spanwise and chordwise directions, as well as twist. The detailed features of real 3D dragonfly wing models, including all the corrugations through both span and chord, have not been considered in the past for a detailed aerodynamic analysis. The simulations were conducted by solving the Navier-Stokes equations to demonstrate gliding performance over a range of angles of attack at low Reynolds numbers. The numerical model was validated against experimental data obtained from a fabricated corrugated wing model using particle image velocimetry. The numerical results demonstrate that bio-inspired wings with corrugations compared to flat profile wings generate more lift with lower drag, trapping the vortices in the valleys of wing corrugation leading to delayed flow separation and delayed stall. The experimental and numerical results demonstrate that the methodology presented in this study can be used to measure bio-inspired 3D wing flow characteristics, including the influence of complex corrugations on aerodynamic performance. These findings contribute to the advancement of knowledge required for designing an optimized bioinspired micro air vehicle.

scholarly journals Impact of Urban Undersea Tunnel Longitudinal Slope on the Visual Characteristics of Drivers

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Shoushuo Wang ◽  
Zhigang Du ◽  
Fangtong Jiao ◽  
Libo Yang ◽  
Yudan Ni
Keyword(s):  
Repeated Measures ◽  
Three Dimensional ◽  
Fixation Time ◽  
Eye Tracker ◽  
Three Dimensional Model ◽  
Longitudinal Slope ◽  
Visual Characteristics ◽  
The Difference ◽  
Vehicle Test ◽  
The Impact

This study aims to investigate the impact of the urban undersea tunnel longitudinal slope on the visual characteristics of drivers. 20 drivers were enrolled to conduct the real vehicle test of the urban undersea tunnel. First, the data of average fixation time and visual lobe were collected by an eye tracker. The differential significance was tested using the one-way repeated measures analysis of variance (ANOVA). Then, the difference between the up-and-down slope (direction) factor and the longitudinal slope (percent) factor on the two indexes were analyzed using the two-way repeated measures ANOVA. Second, by constructing a Lorentz model, the impact of the longitudinal slope on the average fixation time and the visual lobe were analyzed. Besides, a three-dimensional model of the longitudinal slope, average fixation time, and visual lobe was quantified. The results showed that the average fixation time and visual lobe under different longitudinal slopes markedly differed when driving on the uphill and downhill sections. The average fixation time and visual lobe under two factors were markedly different. Moreover, with an increase in the longitudinal slope, the average fixation time exhibited a trend of increasing first then decreasing; the visual lobe exhibited a trend of decreasing first and then increasing. The average fixation time reached the minimum and maximum value when the slope was 2.15% and 4.0%, whereas the visual lobe reached the maximum and minimum value when the slope was 2.88% and 4.0%. Overall, the longitudinal slope exerted a great impact on the visual load of the driver.

Effect of Manufacturing Process on Lined Pipe Bending Response1

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Ilias Gavriilidis ◽  
Spyros A. Karamanos
Keyword(s):  
Manufacturing Process ◽  
Three Dimensional ◽  
Local Buckling ◽  
Numerical Results ◽  
Material Behavior ◽  
Manufacturing Processes ◽  
Three Dimensional Model ◽  
Imperfection Sensitivity ◽  
Mechanical Process ◽  
Inelastic Material

Abstract The effects of manufacturing process on mechanically lined pipe structural performance are investigated. Alternative manufacturing processes are considered, associated with either purely hydraulic or thermo-hydraulic expansion. The problem is solved numerically, accounting for geometric nonlinearities, local buckling phenomena, inelastic material behavior and contact between the two pipes. A three-dimensional model is developed, which simulates the manufacturing process in the first stage of the analysis and, subsequently, proceeds in the bending analysis of the lined pipe. This integrated two-stage approach constitutes the major contribution of the present research. Thermo-hydraulically expanded lined pipes are examined, with special emphasis on the case of partially heated liners, and reverse plastic loading in the liner pipe wall has been detected during depressurization. Furthermore, the numerical results show that the thermo-mechanical process results in higher mechanical bonding between the two pipes compared with the purely mechanical process and that this bonding is significantly influenced by the level of temperature in the liner pipe. It is also concluded that the value of initial gap between the two pipes before fabrication has a rather small effect on the value of liner buckling curvature. Finally, numerical results on imperfection sensitivity are reported for different manufacturing processes, and the beneficial effect of internal pressure on liner bending response is verified.

Fluid Flow and Lateral Fluid Dispersion in Bounded Granular Beds

2002 ◽  
Author(s):  
Azita Soleymani ◽  
Eveliina Takasuo ◽  
Piroz Zamankhan ◽  
William Polashenski
Keyword(s):  
Reynolds Number ◽  
Porous Media ◽  
Numerical Solutions ◽  
Stokes Equations ◽  
Numerical Study ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Numerical Results ◽  
Transition To Turbulence ◽  
Wide Range

Results are presented from a numerical study examining the flow of a viscous, incompressible fluid through random packing of nonoverlapping spheres at moderate Reynolds numbers (based on pore permeability and interstitial fluid velocity), spanning a wide range of flow conditions for porous media. By using a laminar model including inertial terms and assuming rough walls, numerical solutions of the Navier-Stokes equations in three-dimensional porous packed beds resulted in dimensionless pressure drops in excellent agreement with those reported in a previous study (Fand et al., 1987). This observation suggests that no transition to turbulence could occur in the range of Reynolds number studied. For flows in the Forchheimer regime, numerical results are presented of the lateral dispersivity of solute continuously injected into a three-dimensional bounded granular bed at moderate Peclet numbers. Lateral fluid dispersion coefficients are calculated by comparing the concentration profiles obtained from numerical and analytical methods. Comparing the present numerical results with data available in the literature, no evidence has been found to support the speculations by others for a transition from laminar to turbulent regimes in porous media at a critical Reynolds number.

scholarly journals NUMERICAL SOLUTION OF TUMOR-IMMUNE INTERACTION USING 2-POINT BLOCK BACKWARD DIFFERENTIATION METHOD

2012 ◽  
Vol 09 ◽  
pp. 278-284 ◽  
Author(s):  
NOR AIN AZEANY MOHD NASIR ◽  
ZARINA BIBI IBRAHIM ◽  
MOHAMED SULEIMAN ◽  
K. I. OTHMAN ◽  
YONG FAEZAH RAHIM
Keyword(s):  
Numerical Solution ◽  
Numerical Solutions ◽  
Interaction Model ◽  
Numerical Results ◽  
Model Systems ◽  
Computational Time ◽  
Differentiation Formula ◽  
Backward Differentiation Formula ◽  
Differentiation Method ◽  
Interaction System

In this paper, we consider tumor-immune interaction model systems. The numerical solutions for the tumor-immune interaction system are obtained by using the 2-point Block Backward Differentiation Formula (BBDF) methods developed by Zarina et al. in 2007. The numerical results are presented in terms of computational time and accuracy of the solutions.

Effects of the Heat Transfer at the Side Walls on Natural Convection in Cavities

1990 ◽  
Vol 112 (2) ◽  
pp. 370-378 ◽  
Author(s):  
Y. Le Peutrec ◽  
G. Lauriat
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Thermal Conductance ◽  
Fluid Flows ◽  
Heat Losses ◽  
Transfer Rates ◽  
Side Walls ◽  
The Difference

Numerical solutions are obtained for fluid flows and heat transfer rates for three-dimensional natural convection in rectangular enclosures. The effects of heat losses at the conducting side walls are investigated. The problem is related to the design of cavities suitable for visualizing the flow field. The computations cover Rayleigh numbers from 103 to 107 and the thermal conductance of side walls ranging from adiabatic to commonly used glazed walls. The effect of the difference between the ambient temperature and the average temperature of the two isothermal walls is discussed for both air and water-filled enclosures. The results reported in the paper allow quantitative evaluations of the effects of heat losses to the surroundings, which are important considerations in the design of a test cell.

Study on the Airflow Level Posture Sensor Based on Fluid-Solid Coupling

2011 ◽  
Vol 268-270 ◽  
pp. 636-639
Author(s):  
Ming Ming Ji ◽  
Lin Hua Piao ◽  
Bai Hua Li
Keyword(s):  
Tilt Angle ◽  
Model Building ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Three Dimensional Modeling ◽  
Equation Solving ◽  
Dimensional Modeling ◽  
Element Simulation ◽  
Hermetic Chamber ◽  
The Difference

Using ANSYS program, the finite element simulation based on Fluid-Solid coupling is conducted by a series of procedures, such as three-dimensional model building of airflow level posture sensor according to the actual size of the proportion, network modifying, loads applying and equation solving. The flow field in three-dimensional hermetic chamber of sensitive element of airflow level posture sensor is calculated. The numerical results show that: 1) The velocity difference of air flow at two heat source changes with the tilt angle, the difference between airflow velocity increases with the increase of the tilt angle. 2)Compared with two-dimensional modeling, the simulation result of three-dimensional modeling and fluid-solid analysis methods are more comprehensive and accurate, which provides more reliable basis for practical research of the airflow level posture sensor.

Numerical Treatment of the Fractional Modeling on Susceptible-Infected-Recovered Equations with a Constant Vaccination Rate by Using GEM

2019 ◽  
Vol 20 (1) ◽  
pp. 69-75
Author(s):  
M. M. Khader ◽  
M. Adel
Keyword(s):  
Numerical Solution ◽  
Numerical Solutions ◽  
Sir Model ◽  
Vaccination Rate ◽  
Euler Method ◽  
Numerical Results ◽  
Numerical Treatment ◽  
Generalized Euler Method ◽  
Fractional Modeling

AbstractHere, we introduce a numerical solution by using the generalized Euler method for the (Caputo sense) fractional Susceptible-Infected-Recovered (SIR) model with a constant vaccination rate. We compare the obtained numerical solutions with those solutions by using the RK4. Hence, the obtained numerical results of the SIR model show the simplicity and the efficiency of the proposed method.

An Investigation Into the Thermal Behavior of the Grooved Dry Friction Clutch

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Oday I. Abdullah ◽  
Josef Schlattmann
Keyword(s):  
Dry Friction ◽  
Three Dimensional ◽  
Heat Content ◽  
Friction Material ◽  
Area Ratio ◽  
Friction Clutch ◽  
Transient Simulations ◽  
Dry Friction Clutch ◽  
Element Technique ◽  
Nominal Contact Area

The heat generated during the sliding period at the initiation of engagement in friction clutches is considered to be one of the main reasons for the failure of the friction material. One way to reduce the risk of this problem is to increase the rate of heat transfer by convection or, in other words, reduce the heat content of the friction material (internal energy) and thereby increase the lifecycle of the friction clutch. In this paper, the finite element technique has been used to study the effect of radial circumferential grooves on the temperature distribution and the amount of energy transferred by convection for a dry friction clutch disk during a single engagement, assuming a uniform distribution for the thermal load between the contact surfaces (i.e., uniform wear on clutch surfaces). Three-dimensional transient simulations are conducted to study the thermoelastic coupling of the problem. The effect of the groove area ratio (GR, defined as the groove area divided by the nominal contact area) is investigated. Furthermore, this paper presents the equations for energy considerations and energy balance at any time for the friction clutch system. The numerical results show that the amount of energy transferred by convection from the friction material can be controlled (within a limitation) by adjusting the value of the groove area ratio. Commercial ANSYS13 software has been used to perform the numerical computations in this paper.

A Viscous Flow Study of Shock-Boundary Layer Interaction, Radial Transport, and Wake Development in a Transonic Compressor

1992 ◽  
Vol 114 (3) ◽  
pp. 538-547 ◽  
Author(s):  
C. Hah ◽  
L. Reid
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Numerical Solution ◽  
Three Dimensional ◽  
Numerical Results ◽  
Radial Transport ◽  
Layer Interaction ◽  
Transonic Compressor ◽  
Shock Boundary Layer Interaction ◽  
Boundary Layer Interaction

A numerical study based on the three-dimensional Reynolds-averaged Navier–Stokes equation has been conducted to investigate the detailed flow physics inside a transonic compressor. Three-dimensional shock structure, shock-boundary layer interaction, flow separation, radial mixing, and wake development are all investigated at design and off-design conditions. Experimental data based on laser anemometer measurements are used to assess the overall quality of the numerical solution. An additional experimental study to investigate end-wall flow with a hot film was conducted, and these results are compared with the numerical results. Detailed comparison with experimental data indicates that the overall features of the three-dimensional shock structure, the shock-boundary layer interaction, and the wake development are all calculated very well in the numerical solution. The numerical results are further analyzed to examine the radial mixing phenomena in the transonic compressor. A thin sheet of particles is injected in the numerical solution upstream of the compressor. The movement of particles is traced with a three-dimensional plotting package. This numerical survey of tracer concentration reveals the fundamental mechanisms of radial transport in this transonic compressor. Strong radially outward flow is observed inside a separated flow region and this outward flow accounts for about 80 percent of the total radial transport. The radially inward flow is mainly due to the traditional secondary flow.

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