Mohammad Hatami

CFD simulation and optimization of ICEs exhaust heat recovery using different coolants and fin dimensions in heat exchanger

In this paper, finned type heat exchangers with different fin dimensions in the exhaust of a gasoline engine are modeled numerically for improving the exhaust energy recovery. RNG k-ε viscous model is used and the results are compared with available experimental data presented by Lee and Bae (Int J Therm Sci 47:468–478, 2008) where a good agreement is observed. Also, the effect of fin numbers, fin length and three water-based nanofluid coolants (TiO2, Fe2O3 and CuO) on the heat recovery efficiency are investigated in different engine loads. As a main outcome, results show that increasing the fin numbers and using TiO2-water as cold fluid are the most effective methods for heat recover. Furthermore, an optimization analysis is performed to find the best fins dimensions using response surface methodology.

Introduction to Differential Transformation Method

The differential transformation method (DTM) is an alternative procedure for obtaining an analytic Taylor series solution of differential equations. The main advantage of this method is that it can be applied directly to nonlinear differential equations without requiring linearization and discretization, and therefore, it is not affected by errors associated with discretization. The concept of DTM was first introduced to solve linear and nonlinear problems in electrical circuits. This chapter introduces DTM generally and contains the following: 1.1 Introduction

DTM for Fluids Flow Analysis

Studies of fluid transport in biological organisms often concern the flow of a particular fluid inside an expanding or contracting vessel with permeable walls. For a valve, vessel exhibiting deformable boundaries, alternating wall contractions produce the effect of a physiological pump. The flow behavior inside the lymphatic exhibits a similar character. In such models, circulation is induced by successive contractions of two thin sheets, which cause the downstream convection of the sandwiched fluid. Seepage across permeable walls is clearly important to the mass transfer between blood, air, and tissue. Therefore, a substantial amount of research work has been invested in the study of the flow in different geometries in both Newtonian and non-Newtonian form. This chapter introduces differential transformation method to solve these problems, which contains the following sections: 4.1 Introduction

DTM for Nanofluids and Nanostructures Modeling

Nanofluids are produced by dispersing the nanometer-scale solid particles into base liquids with low thermal conductivity such as water, ethylene glycol, oils, etc. The presence of the nanoparticles in the fluids noticeably increases the effective thermal conductivity of the fluid and consequently enhances the heat transfer characteristics. Therefore, numerous methods have been taken to improve the thermal conductivity of these fluids by suspending nano/micro-sized particle materials in liquids. Also nanostructures such as nanobeam, nanotube, etc., have many applications in mechanical engineering. This chapter focuses on the solving problems in this field and contains the following sections: 5.1 Introduction

DTM for Solid Mechanics, Vibration, and Deflection

Most scientific problems in solid mechanics are inherently nonlinear by nature, and, except for a limited number of cases, most of them do not have analytical solutions. The most nonlinear problems in solid mechanics are vibration analysis; deflection and deformation of different beams, materials, or plates. In this chapter some of these problems are presented and solved by DTM, which is categorized in the following sections: 8.1 Introduction

DTM for Heat Transfer Problems

Most of the problems in mechanical engineering include the heat transfer phenomena. Industrial engineering, cooling process, oil industry and melting, shaping and deformations, automobile industry and many other process have a heat transfer and researchers need to control it by increase/decrease devices. Fins are widely used in many industrial applications such as air conditioning, refrigeration, automobile, chemical processing equipment, and electrical chips. Also cooling by suitable fluids such as nanofluids is another application of heat transfer discussed in the present chapter, which contains following sections: 3.1 Introduction

Differential Transformation Method in Advance

Many phenomena in viscoelasticity, fluid mechanics, biology, chemistry, acoustics, control theory, psychology, and other areas of science can be successfully modeled by the use of fractional order derivatives. That is because of the fact that, a realistic modeling of a physical phenomenon having dependence not only at the time instant, but also the previous time history can be successfully achieved by using fractional calculus. Some mechanical problems such as eigenvalue problem, higher-order initial problems, fractional integro-differential equations, etc., the governing equations are some complicated and cannot be solved by the traditional differential transformation method (DTM). This chapter introduces DTM for advance problems and contains the following sections: 2.1 Introduction

DTM for Particles Motion, Sedimentation, and Combustion

Many phenomena are existed in the environment in which particles motion can be observed on them, such as centrifugation, centrifugal filters, industrial hopper, etc. Surface of the motion has different shapes especially for rotating application; it can be a circular, parabolic, or conical surface. Its necessary for scientists to analyze the motion of the particles on these surfaces, so an analytical solution is usually the more preferred method in engineering area because of less computational and high accuracy. Some of them are introduced in these sections: 7.1 Introduction

DTM for Magnetohydrodynamic (MHD) and Porous Medium Flows

In recent years the effect of magnetic field and porous medium in different engineering applications such as the cooling of reactors and many metallurgical processes involves the cooling of continuous tiles has been more considerable. And also, in several engineering processes, materials manufactured by extrusion processes and heat treated materials traveling between a feed roll and a wind up roll on convey belts possess the characteristics of a moving continuous surface, oil industry and combustion, penetration etc., you can find some applications of Magnetohydrodynamic and porous medium. Although in previous chapters some examples were presented, which contained these two important topics, but in this separate chapter some other examples are discussed due to its importance in the following sections: 6.1 Introduction