Parallel Computation of Electric Potential in the EHD Ion-Drag Micropump and the Performance Analysis of the Parallel System

The numerical solution of a computationally intensive model becomes more complex in terms of execution time required by a single processor. To speedup the computation, a suitable parallel computing architecture is required. This paper attempts to achieve a fast finite difference solution of electric potential in an EHD ion-drag micropump. A 2D Poisson’s equation is solved on a cluster of low cost computers using MATLAB. Numerical solution is obtained for the different mesh refinements and then the execution time, communication time, speedup and efficiency of parallel system are analyzed. The results showed that the speedup and efficiency of the system increases by increasing the grid points. The results also reveal that for each data size there is an optimum number of workers for obtaining the parallel numerical solution in minimum processing time

Simulating Electrohydrodynamic Ion-Drag Pumping on Distributed Parallel Computing Systems

Objectives: This paper aims to simulate EHD ion-drag pumping model using Finite Difference Method (FDM) and to apply the idea of parallelism to reduce the computational time. Methods: The numerical simulation of EHD ion-drag pumping plays an important part not only to understand the different working principles but also enables to model the designs with better performance. Since the performance of EHD pumps depends on the shapes and geometries of the actuator electrodes, therefore the variation in the geometric dimensions of the electrodes require dense and fine meshes for numerical solution. Consequently, the numerical simulations take unacceptably more execution time on sequential computers. For that reason, a Data Parallel Algorithm for EHD model (DPA-EHD) is designed. To implement the parallel algorithm a distributed parallel computing system using MATLAB Distributed Computing Server (MDCS) is configured. The computational time and speedup with respect to the different number of processors is evaluated. Findings: This results show that the parallel algorithm for EHD simulations may provide 4.14 times more speedup over sequential algorithm for large grid sizes. Improvements: This study shows the feasibility of using the parallelism to reduce the computational time in the EHD model enabling to simulate the micropumps with very small dimensions of electrodes

Simulation of 2D surface flow in open channel using explicit finite difference method

2D surface flow models are useful to understand and predict the flow through breach, over a dyke or over the floodplains. This paper is aimed at the surface flows to study the behavior of flood waves. The open channel water flow in drains and rivers is considered in view of the fact that such flows are the source of flash flood. In order to predict and simulate the flood behavior a mathematical model with the initial and boundary conditions is established using 2D Saint-Venant partial differential equations. Next, the corresponding model is discretized by using the explicit finite difference method and implemented on MATLAB. For the testing and implementation purpose a simple rectangular flow channel is considered. The output parameters like height or depth of water, the fluid velocity and the volumetric flow rate are simulated numerically and visualized for the different time steps. The initial simulation results are useful to understand and predict the flood behavior at different locations of flow channel at specific time steps and can be helpful in early flood warning systems

Estimation of Carbon Footprints from Diesel Generator Emissions

The aim of this paper is to estimate the amount of carbon footprints emitted from diesel generators in terms of carbon dioxide. A constant load demand of 1.05 kW per hour (6.3 kW/day) with six hours of operation of a diesel generator per day was selected for this analysis. The fuel consumption rate and carbon footprints in terms of carbon dioxide (CO2) were determined. It was discovered that emission of carbon footprints increased by five folds as emission factor was increased from 1kg to 5 kgCO2/liter. Similarly, the increment of a single kW rated power diesel generator at a constant emission factor increases 1.1 to 1.2 times carbon footprint emissions. It is revealed that the efficiency of diesel generator is inversely proportional to its rated power, fuel consumption rate and CO2 emissions. Therefore, the rated power of selected diesel generator should be close to the required load demand

Parallel algorithms for numerical simulations of EHD ion-drag micropump on distributed parallel computing systems

The electrohydrodynamic (EHD) ion-drag micropumps are considered as active components of micro electro mechanical systems (MEMS) such as sensors and detectors. Experimental research on ion-drag micropumps has been carried out in recent years to improve their performance for different applications. But the development of new designs is challenging because of the instrumentation expenditure and microfabrication difficulty. In such circumstances, the numerical simulation of micropumps plays important role not only to understand the different working principles but also enables to model the designs with better performance. Conventionally, the numerical simulations for such devices are obtained by using the commercial simulation packages based on the Finite Element Methods (FEM). However, these simulation packages work on pre-defined built-in functions that do not provide arbitrary control on the governing equations. Since the performance of micropumps depends on the shapes and geometries of the actuator electrodes then the variations in the geometric dimensions of the electrodes require dense and fine meshes. Hence, the numerical simulations take unacceptably more execution time on sequential computers to run the simulation packages. The present study aims to formulate EHD ion-drag pumping model using Finite Difference Method (FDM) which can be easily implemented and provide more control to the user. In addition, the idea of parallelism is applied on the underlying FDM model to reduce the computational time taken for the numerical simulation. A data parallel algorithm (DPA-EHD) is designed and implemented for the EHD equations. The DPA-EHD is further modified by utilizing the pipelining parallelism to reduce the computing iterations and named as data parallel and pipelining algorithm (DPPA-EHD). To implement the parallel algorithms a distributed parallel computing laboratory using easily available low cost computers is setup. The parallel computing laboratory is configured for homogeneous systems using MATLAB Distributed Computing Server (MDCS) with Windows 7 operating system. The designed algorithms are implemented for EHD equations and their performance is evaluated by using different performance indicators. The results showed that the parallel algorithms for EHD simulations may provide 4 to 5 times more speedup over sequential algorithm for large grid sizes. This demonstrates the feasibility of using the FDM and parallel computing to reduce the computational time in the EHD model enabling to simulate the micropumps with very small dimensions of electrodes. In order to evaluate the scalability at specific data size the appropriate regression models are fitted through the measured data as functions of number of workers. The idea for selection of optimum number of workers is presented for future work in this direction. Hence, the research contributes for the reduction of computing time in the numerical simulation of EHD equations specifically and generally those solved by using FDM

Parallel Numerical Solution of 2D Electrostatics Poisson Equation on Different Mesh Partitioning Schemes

The ideas of parallelism for the large scale problems or problems with dense meshes have gained much attention in last few decades. The key goal of applying the parallelization is to reduce the computational time. In this paper; the 2D finite difference mesh partitioning schemes and their effect on performance of parallel numerical solution is evaluated. The main objective was to investigate the mesh partitioning schemes for less computational time and high speedup. For testing and implementation purpose a 2D electrostatics Poisson’s equation with Dirichlet and Neumann boundary conditions applied on a 2D cross section of Electrohydrodynamic (EHD) planar ion-drag micropump is used to simulate the electric potential and electric field on a parallel system. The performance of the 7 different mesh partitioning schemes (PS) in terms of computational time, speedup, efficiency and communication cost was evaluated. It was revealed that among the seven different partitioning schemes the PS-3 (two-way or tile partitioning) is found the best scheme for the parallel numerical simulation of the problem. Moreover, the parallel algorithm remains more efficient on $P=2$ to $P=8$ workers while for P>8 the efficiency of the algorithm may drop because of the high communication time