scholarly journals Numerical Simulation of Flow within a storage area of HDPE modular pavement

2021 ◽  
Vol 920 (1) ◽  
pp. 012044
Author(s):  
A S N Amirah ◽  
F Y Boon ◽  
K A Nihla ◽  
Z M Salwa ◽  
A W Mahyun ◽  
...  

Abstract The development of stromwater management usually promote to provide the safe passage of stromwater. However physical modelling need expensive laboratory experiments. Due to that this numerical study is performed to study the flow within storage area of HDPE modular pavement. This paper studied and compared the infiltration rate of diagonal modular and conventional pavement (control), determined the velocity magnitude and pressure of modular pavement at various rainfall intensities. FLOW-3D was used to run a simulation on a porous media flow model using the Navier-Stokes equation. Real rainfall data of Malaysia was used as the model inputs to get better analysis of pavement design. The present findings showed that storage area modular pavement has lower fraction of fluid than control, which means that it has greater holding capacity and capable to capture all the rainfall volume from 5mm/h to 85mm/h. Besides, rainfall intensity has a strong influence on velocity magnitude and pressure. The HDPE diagonal modular pavement strong enough to sustain with an increasing of velocity magnitude and pressure during extreme rainfall. Therefore, HDPE modular pavement indicates a better water interception capacity than conventional pavement. FLOW-3D helps the critical analysis of pavement design process and useful as supplementary tool.

Author(s):  
K. Vijaykumar ◽  
S. Poonkodi ◽  
A.T. Sriram

Sunroof has become one of the essential features of a luxury car, and it provides natural air circulation and good illumination into the car. But the primary problem associated with it is the buffeting noise which causes discomfort to the passengers. Though adequate studies were carried out on sunroof buffeting, efficient control techniques are needed to be developed from fundamental mechanism. To reduce the buffeting noise, flow modifications at the entrance of the sunroof is considered in this study. The internal portion of the car with sunroof is simplified into a shear driven open cavity, and two-dimensional numerical simulations are carried out using commercial solver, ANSYS Fluent. Reynolds averaged Navier-Stokes equation is used with the realizable k-? turbulence model. The unsteady numerical result obtained in this study is validated with the available experimental results for the dominant frequency. The prediction is good agreement with experiment. Flow modification technique is proposed to control the sunroof buffeting by implementing geometric modifications. A hump has been placed near the leading edge of the cavity which resulted in significant reduction of pressure oscillations. Parametric studies have been performed by varying the height of hump and the distance of hump from the leading edge. There is no prominent difference when the height of the hump is varied. As the distance of the hump from the leading edge is reduced, the sound pressure level decreases.


Author(s):  
Nur Alom ◽  
Ujjwal K. Saha

The Savonius rotor appears to be particularly promising for the small-scale applications because of its design simplicity, good starting ability, and insensitivity to wind directions. There has been a growing interest in recent times to harness wind energy in an efficient manner by developing newer blade profiles of Savonius rotor. The overlap ratio (OR), one of the important geometric parameters, plays a crucial role in the turbine performance. In a recent study, an elliptical blade profile with a sectional cut angle (θ) of 47.5° has demonstrated its superior performance when set at an OR = 0.20. However, this value of OR is ideal for a semicircular profile, and therefore, requires further investigation to arrive at the optimum overlap ratio for the elliptical profile. In view of this, the present study attempts to make a systemic numerical study to arrive at the optimum OR of the elliptical profile having sectional cut angle, θ = 47.5°. The 2D unsteady simulation is carried out around the elliptical profile considering various overlap ratios in the range of 0.0 to 0.30. The continuity, unsteady Reynolds Averaged Navier-Stokes (URANS) equations and two equation eddy viscosity SST (Shear Stress transport) k-ω model are solved by using the commercial finite volume method (FVM) based solver ANSYS Fluent. The torque and power coefficients are calculated as a function of tip speed ratio (TSR) and at rotating conditions. The total pressure, velocity magnitude and turbulence intensity contours are obtained and analyzed to arrive at the intended objective. The numerical simulation demonstrates an improved performance of the elliptical profile at an OR = 0.15.


2012 ◽  
Vol 249-250 ◽  
pp. 517-522 ◽  
Author(s):  
Yu Long Lei ◽  
Jie Tao Wen ◽  
Xing Zhong Li ◽  
Cheng Yang

In order to evaluate the efficacy of grooves on cooling performance of wet clutch, a numerical analysis based on the computational fluid dynamics (CFD) code FLUENT is presented in this study. This analysis is based on the numerical solution of the three-dimensional Navier-Stokes equation, coupled with the energy equation in the flow and the heat conduction equations in the friction material and the core disk. The turbulence characteristics were predicted using RNGk-ε model. The flow field and temperature distributions in radial grooves are obtained. It is shown that radial grooves possess the highest heat exchange performance at the entrance and is not linear distribution in the radial direction and cooling oil flow has a little effect on the highest temperature of friction plate. With the developed analysis method, it is possible to easily and quickly investigate the heat transfer behaviour of wet cluth with groove patterns.


Author(s):  
Adnan Anwar ◽  
Mudassar Razzaq ◽  
Liudmila Rivkind

As an example of an aerodynamics prototypical study, we examined a two-dimensional low Reynolds number flow over obstacles immersed in a stream of infinite extent. The Navier Stokes equation is being discretized by non conforming finite element method approach. The resulting discretized nonlinear algebraic system is being solved by using the fixpoint method and the Newton method and multigrid method for the linear sub-problem employed. The magnitude of the uniform upstream velocity under the study of the problem for Reynolds number in the range 1 < Re < 100 and the angle of attack of the upstream velocity at α = -5; 0; 5 degrees performed. Analysis of the resulting drag and lift forces acting on obstacles with respect to the angle of attack of the upstream velocity and the Reynolds number is made. Moreover, the influence of one obstacle on the resulting drag and lift coefficients of other obstacles determined. The results are being presented in a graphical and vector form.


2009 ◽  
Vol 6 (4) ◽  
pp. 189-197
Author(s):  
Ravi Bhadauria ◽  
Ramana M. Pidaparti ◽  
Mohamed Gad-el-Hak

A design optimization based on coupled solid–fluid analysis is investigated in this paper to achieve specific flow rate through a peristaltic micropump. A micropump consisting of four pneumatically actuated nozzle/diffuser shaped moving actuators on the sidewalls is considered for numerical study. These actuators are used to create pressure difference in the four pump chambers, which in turn drives the fluid through the pump in one direction. Genetic algorithms along with artificial neural networks are used for optimizing the pump geometry and the actuation frequency. A simple example with moving walls is considered for validation by developing an exact analytical solution of the Navier–Stokes equation and comparing it with numerical simulations. Possible applications of these pumps are in microelectronics cooling and drug delivery. Based on the results obtained from the fluid–structure interaction analysis, three optimized geometries result in flow rates that match the predicted flow rates with 95% accuracy. These geometries need further investigation for fabrication and manufacturing issues.


2004 ◽  
Vol 126 (3) ◽  
pp. 399-409 ◽  
Author(s):  
A. Britan ◽  
A. V. Karpov ◽  
E. I. Vasilev ◽  
O. Igra ◽  
G. Ben-Dor ◽  
...  

The flow developed behind shock wave transmitted through a screen or a perforated plat is initially highly unsteady and nonuniform. It contains multiple shock reflections and interactions with vortices shed from the open spaces of the barrier. The present paper studies experimentally and theoretically/numerically the flow and wave pattern resulted from the interaction of an incident shock wave with a few different types of barriers, all having the same porosity but different geometries. It is shown that in all investigated cases the flow downstream of the barrier can be divided into two different zones. Due immediately behind the barrier, where the flow is highly unsteady and nonuniform in the other, placed further downstream from the barrier, the flow approaches a steady and uniform state. It is also shown that most of the attenuation experienced by the transmitted shock wave occurs in the zone where the flow is highly unsteady. When solving the flow developed behind the shock wave transmitted through the barrier while ignoring energy losses (i.e., assuming the fluid to be a perfect fluid and therefore employing the Euler equation instead of the Navier-Stokes equation) leads to non-physical results in the unsteady flow zone.


2012 ◽  
Vol 220-223 ◽  
pp. 2437-2444
Author(s):  
Yun Tao Wang ◽  
Guang Xue Wang ◽  
De Hong Meng ◽  
Song Li

Numerical simulations for the flows of typical transport configurations are performed by solving Navier-Stokes equation using TRIsonic Platform (TRIP). The purpose is to validate TRIP3.0 for the simulation of transport configurations. The configurations contain DLR-F6 and trapezoidal high lift configurations. For DLR-F6, the structured mesh and test data are obtained from DPW-III. The reference numerical results are obtained by CFL3D. For the high lift configurations, the structured mesh are generated with ICEM, and test data are obtained from HiLiftPW-1. For these configurations, the effects of grid density to aerodynamic characteristics are systematically studied. The numerical results are verified by comparison with experimental data and numerical results of CFL3D. Grid refinement leads to converged numerical results. It is demonstrated that grid density has little influence on friction drag, whereas significant influence on pressure drag for the DLR-F6 configurations. It has little influence on lift and momentum for the trapezoidal high lift configurations before stall, but has obvious influence near stall.


2015 ◽  
Vol 72 (9) ◽  
pp. 3685-3698 ◽  
Author(s):  
Kai-Yuan Cheng ◽  
Pao K. Wang ◽  
Tempei Hashino

Abstract The fall attitudes and the flow fields of falling hexagonal ice plates are studied by numerically solving the transient incompressible Navier–Stokes equation for flow past ice plates and the body dynamics equations representing the 6-degrees-of-freedom motion that determine the position and orientation of the ice plates in response to the hydrodynamic force of the flow fields. The ice plates investigated are from 1 to 10 mm in diameter, and the corresponding Reynolds number ranges from 46 to 974. The results indicate that the 1-mm plate generates a steady flow field and exhibits a steady motion, whereas the rest of the ice plates generate unsteady flow fields and exhibit unsteady motions, including horizontal translation, rotation, and axial oscillation. The horizontal translation is primarily determined by the inclination due to oscillation. The pressure distributions around the falling plates are examined and discussed in association with the oscillation. The vortex structure in the wake of the plate is examined. Empirical formulas for fall speed, oscillation frequency, and drag coefficient are given. Potential impacts of the fall attitudes and flow characteristics on the microphysics of ice plates are discussed.


2020 ◽  
Vol 14 (3) ◽  
pp. 7181-7190
Author(s):  
Sathvik Nayak H. S. ◽  
Nitesh Kumar ◽  
S. M. A. Khader ◽  
Raghuvir Pai

Image-based Computational Fluid Dynamic (CFD) simulations of anatomical models of human arteries are gaining clinical relevance in present days. In this study, CFD is used to study flow behaviour and hemodynamic parameters in aneurysms, with a focus on the effect of geometric variations in the aneurysm models on the flow dynamics. A computational phantom was created using a 3D modelling software to mimic a spherical aneurysm. Hemodynamic parameters were obtained and compared with the available literature to validate. Further, flow dynamics is studied by varying the dome size of the aneurysm from 3.75 mm to 6.25 mm with an increment of 0.625 mm keeping the neck size constant. The aneurysm is assumed to be located at a bend in the arterial system. Computational analysis of the flow field is performed by using Navier – Stokes equation for laminar flow of incompressible, Newtonian fluid. Parameters such as velocity, pressure, wall shear stress (WSS), vortex structure are studied. It was observed that the location of the flow separation and WSS vary significantly with the geometry of the aneurysm. The reduction of WSS inside the aneurysm is higher at the larger dome sizes for constant neck size.


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