Dr. Muhaimin Ismoen - Academia.edu (original) (raw)

Papers by Dr. Muhaimin Ismoen

Frontiers in Mechanical Engineering

The aim of this study is to investigate the thermal performance of water-based Carbon Nano Materi... more The aim of this study is to investigate the thermal performance of water-based Carbon Nano Material (CNM) nanofluids, particularly in the convective heat transfer coefficient (h) parameter, and to analyze the effects of nanoparticle concentration and flow rate on an experimental heat transfer system. To achieve this, the researchers prepared the nanofluid through a 2-step method. In the first step, we mixed the nanoparticles with the base fluid using a magnetic stirrer to ensure homogenization, with the CNM-Water ratio set at 30, 75, 120, and 150 ppm. In the second step, we characterized the prepared samples, determining their size, composition, and particle morphology through PSA and SEM-EDX examination, as well as measuring their density (ρ) and specific heat (Cp). The experiments were carried out using a flow rate simulation test rig with a data acquisition system, at different flow rates of 0.2, 0.6, 1, and 1.4 L/min. Temperature (T) was measured at the inlet, outlet, and heater...

Tsunami and inundation modelling due to far field tsunami propagation in a limited area is a very... more Tsunami and inundation modelling due to far field tsunami propagation in a limited area is a very challenging numerical task because it involves many aspects such as the formation of various types of waves and the irregularities of coastal boundaries. To compute the effect of far field tsunami and extent of inland inundation due to far field tsunami along the coastal belts of west coast of Malaysia and Southern Thailand, a formulated boundary condition and a moving boundary condition are simultaneously used. In this study, a boundary fitted curvilinear grid system is used in order to incorporate the coastal and island boundaries accurately as the boundaries of the model domain are curvilinear in nature and the bending is high. The tsunami response of the event 26 December 2004 along the west open boundary of the model domain is computed to simulate the effect of far field tsunami. Based on the data of the tsunami source at the west open boundary of the model domain, a boundary condi...

ABSTRACT A boiler drum and heat exchanger QAD Model BDT921 that is installed in the Control Labor... more ABSTRACT A boiler drum and heat exchanger QAD Model BDT921 that is installed in the Control Laboratory Universiti Tun Hussein Onn Malaysia (UTHM) is being used as a model plant to achieve the digital control system design since it is analog in nature. The digital control design need a mathematical model of the system is designed. This paper covers a simulation of various PI controllers setting for boiler drums T11 QAD Model BDT 921. The model is obtained from parameter gain values of the real system and then this model will simulate using SIMULINK program. The proportional plus integral (PI) controllers are being chosen as the control element in this model as the real system is using the same control element. The output display is the characteristic of the system modeled. The tuning values are fixed for proportional gain while the integral time is changed to 10s, 20s, 30s, and 40s. From the signal generated that the trend of tuning the PI setting value will be compared in order to see the difference in damping. There are three type of damping exist in second order system. Those are under damped, critically damped and over damped signals. With regarding to the analysis done, the digital control can be implemented to the boiler drum and heat exchanger control system and for further viewing, to be controlled digitally with computer in the control room

Mathematical Problems in Engineering, 2014

The oscillatory free convection about a horizontal circular cylinder in a Newtonian fluid in the ... more The oscillatory free convection about a horizontal circular cylinder in a Newtonian fluid in the presence of heat generation is investigated numerically by using the finite difference method. The surface temperature of the cylinder oscillates harmonically about the temperature of the surrounding medium. Heat is generated internally within the Newtonian fluid at a rate proportional to a power of the temperature difference. It is found that the presence of heat generation significantly increases the temperature and velocity distribution. The effects of the heat generation parameter and the Prandtl number on the surface rate of heat transfer, in terms of the local Nusselt number, and the surface shear stress, in terms of the local skin friction, are shown graphically from the stagnation point of the circular cylinder.

International Journal of Innovation in Mechanical Engineering and Advanced Materials, 2015

The similarity and non-similarity analysis are presented to investigate the effect of buoyancy fo... more The similarity and non-similarity analysis are presented to investigate the effect of buoyancy force on the steady flow and heat transfer of fluid past a heated wedge. The fluid is assumed to be a Newtonian, viscous and incompressible. The wall of the wedge is an impermeable with power law free stream velocity and a wall temperature. Due to the effect of a buoyancy force, a power law of free stream velocity and wall temperature, then the flow field is similar when n = 2m - 1, otherwise is non-similar when n ≠ 2m - 1. The governing boundary layer equations are written into dimensionless forms of ordinary differential equations by means of Falkner-Skan transformation. The resulting ordinary differential equations are solved by Runge-Kutta Gill with shooting method for finding a skin friction and a rate of heat transfer. The effects of buoyancy force and non-uniform wall temperature parameters on the dimensionless velocity and temperature profiles are shown graphically. Comparisons wit...

The effects of radiation and suction or injection with variable viscosity on mixed convection hea... more The effects of radiation and suction or injection with variable viscosity on mixed convection heat and mass transfer of a Newtonian, viscous and incompressible fluid over a permeable surfaces embedded in porous medium was analyzed using similarity transformation. The governing boundary layer equations are written into a dimensionless form by using Falkner-Skan transformation. The resulting ordinary differential equations are of two-point boundary value problem which are solved by Runge-Kutta-Gill in conjunction with shooting method for finding skin friction, rate of heat and mass transfer. The effects of variable viscosity, suction or injection in the presence of thermal radiation on the dimensionless velocity, temperature and concentration profiles are shown graphically. Comparisons with previously published works are performed and excellent agreement between the results is obtained. The conclusion is drawn that the flow filed and temperature profiles are significantly influenced b...

International Journal of Advances in Intelligent Informatics

This paper's focal point is on the nonstandard Optimal Control (OC) problem. In this matter, ... more This paper's focal point is on the nonstandard Optimal Control (OC) problem. In this matter, the value of the final state variable, y(T) is said to be unknown. Moreover, the Lagrangian integrand in the function is in the form of a piecewise constant integrand function of the unknown state value y(T). In addition, the Lagrangian integrand depends on the y(T) value. Thus, this case is considered as the nonstandard OC problem where the problem cannot be resolved by using Pontryagin’s Minimum Principle along with the normal boundary conditions at the final time in the classical setting. Furthermore, the free final state value, y(T) in the nonstandard OC problem yields a necessary boundary condition of final costate value, p(T) which is not equal to zero. Therefore, the new necessary condition of final state value, y(T) should be equal to a certain continuous integral function of y(T)=z since the integrand is a component of y(T). In this study, the 3-stage piecewise constant integran...

International Journal of Engineering & Technology

Optimization is the selection of a best element with regards to certain criterion from set of ava... more Optimization is the selection of a best element with regards to certain criterion from set of available alternatives. This paper investigates the effects of assets in optimizing risk using diversification strategy and also examines gold quality of hedging and safe haven. The reduction strength of assets is estimated. Hence, it is observed that gold exhibits highest risk reduction strength. Also it is noticed that gold acts as hedge and safe haven for investors during economic recession.

Materials Science Forum

The performance of carbon nanotube (CNT) nanofluids on convective heat transfer over a stretching... more The performance of carbon nanotube (CNT) nanofluids on convective heat transfer over a stretching sheet was investigated under thermal stratification and magnetic field effects. Water, engine oil and ethylene glycol are used as the base fluids. The governing equations are transformed into a system of coupled nonlinear ordinary differential equations using similarity transformations and solved numerically using the fourth-order Runge–Kutta–Fehlberg in conjunction to shooting method. The CNT nanofluids with an engine oil base fluid shows the highest thermal conductivity in comparison to ethylene glycol and water, respectively. Potential application of the thermal conductivity enhancement of CNT nanofluid is to increase the energy-efficient mechanical systems in heating, cooling and ventilation of the indoor environment.

Journal of Applied & Computational Mathematics

Combined heat and mass transfer on mixed convection non-similar flow of electrically conducting n... more Combined heat and mass transfer on mixed convection non-similar flow of electrically conducting nanofluid along a permeable vertical plate in the presence of thermal radiation is investigated. The governing partial differential equations of the problem are transformed into a system of non linear ordinary differential equations by applying the Sparrow–Quack–Boerner local non-similarity method (LNM). Furthermore, the obtained equations are solved numerically by employing the Fourth or fifth order Runge Kutta Fehlberg method with conjunction to shooting technique. The profiles of flow and heat transfer are verified by using five types of nanofluids of which metallic or nonmetallic nanoparticles, namely Copper (Cu), Alumina (Al2O3), Copper oxide (CuO), silver (Ag) and Titanium (TiO2) with a water-based fluid. Rosseland approximation model on black body is used to represent the radiative heat transfer. Effects of thermal radiation, buoyancy force parameters and volume fraction of nanofluid on the velocity and temperature profiles in the presence of suction/injection are depicted graphically. Comparisons with previously published works are performed, and excellent agreement between the results is obtained. The conclusion is that the flow fields is affected by these parameters.

Indian Journal of Science and Technology, 2015

Background/Objectives: The objective of the present work is to investigate the effects of the the... more Background/Objectives: The objective of the present work is to investigate the effects of the thermophoresis and the fluid viscosity on a forced convection heat and mass transfer on non-similar flow past a permeable wedge embedded in a porous medium. Methods of Analysis: The analysis is conducted by using a local non-similarity scheme of the second level truncation in the presence of thermophoresis and variable viscosity. The governing equations of the non-similar convection are presented in the dimensionless form by applying Falkner-Skan variable to obtain the set of ordinary differential equations. Runge-Kutta-Gill in conjunction with shooting method is applied to find a skin friction, rate of heat and mass transfer. The initial value problems are solved numerically using Runge Kutta-Fehlberg methods and presented graphically. Findings: The thermophoresis has significant effect to speed up the process for decreasing concentration significantly, while the effects of viscosity is to increase or decrease the velocity of fluid depend on the value of viscosity parameter, positive or negative, respectively. Validation is conducted by comparing the current works with previous works and found that the results are in excellent agreement. The conclusion is drawn that the non-similar velocity and the concentration of fluid are significantly affected by thermophoresis and viscosity. Application/Improvements: The results of an analysis on the effects of thermophoresis and viscosity on boundary layer flow over solid surfaces can be applied to design an instrument to remove pollutants from environment

Engineering Science and Technology, an International Journal, 2015

Abstract Single walled carbon nanotube, alumina and copper nanoparticles on convective mass trans... more Abstract Single walled carbon nanotube, alumina and copper nanoparticles on convective mass transfer in the presence of base fluid (water) over a horizontal plate are investigated numerically. The governing partial differential equations with auxiliary conditions are reduced into the system of coupled ordinary differential equations via similarity transformation and it has been solved numerically using fourth or fifth order Runge–Kutta–Fehlberg method with shooting technique. The results display that the diffusion boundary layer thickness of the water based Cu and SWCNTs is stronger than Al2O3–water with increase of chemical reaction.

Effect of radiation on free convection on heated horizontal circular has been investigated. The c... more Effect of radiation on free convection on heated horizontal circular has been investigated. The cylinder is fixed and immersed in a stationary fluid, in which the temperature is uniformly heated about the temperature of the surrounding fluid. The governing equation are transformed into dimensionless non-linear of partial differential equations and solved numerically by employing a finite difference method. An implicit finite difference scheme of Crank Nicolson method is used to analyze the results. This study determine the effects of radiation parameter, heat generation parameter, and the Prandtl number, , on the temperature and velocity profiles. The results of the local heat transfer and skin-friction coefficient in the presence of radiation for some selected values of Prandtl number and heat generation parameter have shown graphically.

This study investigates free convection about a heated infinite horizontal circular cylinder in a... more This study investigates free convection about a heated infinite horizontal circular cylinder in a Newtonian fluid in the presence of heat generation. The cylinder is fixed and immersed in a stationary fluid, in which the temperature is uniformly heated about the temperature of the surrounding fluid. The governing equation is non-dimensionlized and solved numerically by employing a finite difference method. The effects of heat generation parameter,γ and the Prandtl number, Pr, of the temperature and velocity profile are shown graphically. It is found that the presence of heat generation significantly increases the temperature and velocity distribution thus as Pr increases, the temperature and velocity distribution decrease too.

Applied Mathematics and Mechanics, 2009

An analysis is presented to investigate the effects of variable viscosities and thermal stratific... more An analysis is presented to investigate the effects of variable viscosities and thermal stratification on the MHD mixed convective heat and mass transfer of a viscous, incompressible, and electrically conducting fluid past a porous wedge in the presence of a chemical reaction. The wall of the wedge is embedded in a uniform non-Darcian porous medium in order to allow for possible fluid wall suction or injection. The governing boundary layer equations are written into a dimensionless form by similarity transformations. The transformed coupled nonlinear ordinary differential equations are solved numerically with finite difference methods. Numerical calculations up to the thirdorder level of truncation are carried out for different values of dimensionless parameters. The results are presented graphically, and show that the flow field and other quantities of physical interest are significantly influenced by these parameters. The results are compared with those available in literature, and show excellent agreement.

Nuclear Engineering and Design, 2010

This paper concerns with a steady two-dimensional flow of an electrically conducting incompressib... more This paper concerns with a steady two-dimensional flow of an electrically conducting incompressible fluid over a vertical stretching surface. The flow is permeated by a uniform transverse magnetic field. The fluid viscosity is assumed to vary as a linear function of temperature. A scaling group of transformations is applied to the governing equations. The system remains invariant due to some

Journal of Porous Media, 2010

The Adomian decomposition method with Padé approximants is employed in this study as a simple, no... more The Adomian decomposition method with Padé approximants is employed in this study as a simple, non-perturbative alternative to solve the magnetohydrodynamic (MHD) boundary-layer flow due to a permeable shrinking sheet embedded in a porous ...