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Showing 16 results for Shojaeefard

M. H. Shojaeefard, I. Sohrabiasl, E. Sarshari,
Volume 1, Issue 2 (6-2011)
Abstract

Intake system design as well as inlet ports and valves configuration is of paramount importance in the optimal performance of internal combustion engines. In the present study, the effect of inlet ports design is investigated on OM-457LA diesel engine by using a CFD analysis and the AVL-Fire code as well. A thermodynamic model of the whole engine equipped with a turbocharger and an intercooler is used to obtain the initial and boundary conditions of the inlet and outlet ports of the engine cylinder which are necessary for performing the three dimensional CFD analysis. The intake stroke as well as the compression and power strokes are included in this three dimensional CFD model. As a mean of validation the performance of the engine model with the base configuration of the inlet ports is compared to the experimental data. Two new alternative configurations for the inlet ports are then investigated with respect to the turbulence levels of the in-cylinder flow and the combustion characteristics as well. Finally it is demonstrated that applying the new configurations results in circa 75% reduction in nitric oxide formation besides increase of 32% in the in-cylinder flow swirl.


M. H. Shojaeefard, R. Talebitooti, M. Amirpour Molla, R. Ahmadi,
Volume 2, Issue 1 (1-2012)
Abstract


M. H. Shojaeefard, M. M. Etghani, M. Tahani, M. Akbari,
Volume 2, Issue 4 (10-2012)
Abstract

In this study the performance and emissions characteristics of a heavy-duty, direct injection, Compression ignition (CI) engine which is specialized in agriculture, have been investigated experimentally. For this aim, the influence of injection timing, load, engine speed on power, brake specific fuel consumption (BSFC), peak pressure (PP), nitrogen oxides (NOx), carbon dioxide (CO2), Carbon monoxide (CO), hydrocarbon (HC) and Soot emissions has been considered. The tests were performed at various injection timings, loads and speeds. It is used artificial neural network (ANN) for predicting and modeling the engine performance and emission. Multi-objective optimization with respect to engine emissions level and engine power was used in order to deter mine the optimum load, speed and injection timing. For this goal, a fast and elitist non-dominated sorting genetic algorithm II (NSGA II) was applied to obtain maximum engine power with minimum total exhaust emissions as a two objective functions.


M.h. Shojaeefard, R. Talebitooti, S. Yarmohammadisatri, M. Torabi,
Volume 3, Issue 1 (3-2013)
Abstract

In this paper, a method based on binary-coded genetic algorithm is proposed to explore an optimization method, for obtaining an optimal elliptical tank. This optimization method enhances the rollover threshold of a tank vehicle, especially under partial filling conditions. Minimizing the overturning moment imposed on the vehicle due to c.g. height of the liquid load, lateral acceleration and cargo load shift are properly applied. In the process, the width and height of tanker are assumed as constant parameters. Additionally, considering the constant cross-sectional area, an optimum elliptical tanker of each filling condition is presented to provide more roll stability. Moreover, the magnitudes of lateral and vertical translation of the cargo within the proposed optimal cross section under a constant lateral acceleration field are compared with those of conventional elliptical tank to demonstrate the performance potentials of the optimal shapes. Comparing the vehicle rollover threshold of proposed optimal tank with that of currently used elliptical and circular tank reveals that the optimal tank is improved approximately 18% higher than conventional one.


M. H. Shojaeefard, M. Tahani, M. M. Etghani, M. Akbari,
Volume 3, Issue 3 (9-2013)
Abstract

Cooled exhaust gas recirculation is emerging as a promising technology to address the increasing demand for fuel economy without compromising performance in turbocharged spark injection engines. The objectives of this study are to quantify the increase in knock resistance and to decrease the enrichment and emission at high load. For this purpose four stroke turbo charged Spark Ignition engine (EF7-TC) including its different systems such as inlet and exhaust manifold, exhaust pipe and engine geometry are modeled using GT Power Software. As predicted, using cooled EGR at high load enabled operation at lambda near to one with the same serial engine performances, which offers substantial advantages Such As BSFC reduction (up to 14%), and emission reduction (CO, NOx).


M.h. Shojaeefard, V.kh. Mousapour, M.sh. Mazidi,
Volume 4, Issue 1 (3-2014)
Abstract

Thermal Contact Conductance (TCC) between an exhaust valve and its seat is one of the important parameters to be estimated in an internal combustion engine. An experimental study presented here to acquire temperature in some interior points to be used as inputs to an inverse analysis. An actual exhaust valve and its seat are utilized in a designed and constructed setup. Conjugate Gradient Method (CGM) with adjoin problem for function estimation is used for estimation of TCC. The method converges very rapidly and is not so sensitive to the measurement errors. Contact frequency is one the factors which have a significant influence on TCC. The results obtained from current inverse method as well as those obtained from linear extrapolation method show that the thermal contact conductance decreases as the contact frequency increases. The results obtained from both sets of results are also in good agreement.


M.h. Shojaeefard, V.kh. Mousapour, M.sh. Mazidi,
Volume 4, Issue 1 (3-2014)
Abstract

Thermal Contact Conductance (TCC) between an exhaust valve and its seat is one of the important parameters to be estimated in an internal combustion engine. An experimental study presented here to acquire temperature in some interior points to be used as inputs to an inverse analysis. An actual exhaust valve and its seat are utilized in a designed and constructed setup. Conjugate Gradient Method (CGM) with adjoin problem for function estimation is used for estimation of TCC. The method converges very rapidly and is not so sensitive to the measurement errors. Contact frequency is one the factors which have a significant influence on TCC. The results obtained from current inverse method as well as those obtained from linear extrapolation method show that the thermal contact conductance decreases as the contact frequency increases. The results obtained from both sets of results are also in good agreement.


H. Shojaeefard , M. Hakimollahi , M. Kashefi,
Volume 4, Issue 2 (6-2014)
Abstract

Having a full understanding of the world’s social-economic situation is the success key for industries automotive manufacturing industry is an extremely competitive one usually there is no clear guideline among automotive companies about technological causes behind their success and failure. This research provides an investigation about the world’s economic situation and the environmental situation surrounded the automotive industry, than will focus on chines auto industry. Automotive manufacturers and suppliers view China as the largest combination of automotive market and low-cost manufacturing and supply base to appear in decades. Companies are deluged with information about the potential opportunities in China, but typically know very little about what the Chinese think about their automotive future. The steady influx of automotive manufacturers and suppliers over the past ten years has provided the Chinese with firsthand experience of what the impact of a world-class, high-volume automotive industry can mean to a country.


H. Shojaeefard, M. Hakimollahi,
Volume 5, Issue 3 (9-2015)
Abstract

The new product development (NPD) is the process by which a new product idea is conceived, investigated, taken through the design process, manufactured, marketed and serviced. In Automotive Engineering these related to the product realization process (PRP) which consists of five phases: "Plan and Define Program", "Product Design and Development", "Process Design and Development", "Product and Process Validation", and "Production Launch, Feedback Assessment and Corrective Action". This paper proposes a process-based management concept focusing on controlling and measuring for their effective management including literature review of NPD performance measurement. Integrating the process-based management concept with the proper performance measure can initiate new knowledge which will contribute to the improvement of the automotive industry.


M.h. Shojaeefard, G.r. Molaeimanesh, N. Aghamirzaei, S. Ghezelbiglo, B. Zeinolabedini,
Volume 5, Issue 4 (12-2015)
Abstract

Due to the increasing development in various branches of the automotive industry, the need for a comfort climate in the cabin is more sensible. However, to achieve climate comfort, HVAC system consumes a considerable amount of engine power. Hence, improving HVAC system performance leads to more energy saving of the vehicle which is a critical factor for nowadays automotive. Besides, one crucial task of HVAC system is defrosting/defogging of windshield which is considered as a mandatory requirement in most countries. In the current study, the defrosting/defogging performance of HVAC system in the main product of national vehicle platform is numerically evaluated based on the ECE-78-715 legal requirement. For this purpose, after validation and mesh independency study, the transient air flow in three-dimensional cabin geometry is simulated by SSTk-ω turbulence model via ANSYS Fluent software and the windshield thermal condition is reported during defrosting/defogging. Besides, two national HVAC standards of AERC-10-01 and AERC-10-02 are also checked. The results demonstrate that HVAC system of the main product of the national vehicle platform can satisfactorily fulfill ECE-78-715, AERC-10-01 and AERC-10-02.


M.h. Shojaeefard, S. Ebrahimi Nejad, M. Masjedi,
Volume 6, Issue 1 (3-2016)
Abstract

In this article, vehicle cornering stability and brake stabilization via bifurcation analysis has been investigated. In order to extract the governing equations of motion, a nonlinear four-wheeled vehicle model with two degrees of freedom has been developed. Using the continuation software package MatCont a stability analysis based on phase plane analysis and bifurcation of equilibrium is performed and an optimal controller has been proposed. Finally, simulation has been done in Matlab-Simulink software considering a sine with dwell steering angle input, and the effectiveness of the proposed controller on the aforementioned model has been validated with Carsim model.


M.h. Shojaeefard, M. Hakimollahi,
Volume 6, Issue 2 (6-2016)
Abstract

New product development (NPD) is described in the literature as the transformation of a market opportunity into a product available for sale [ ]. In the automotive industry, within the context of ISO/TS (the automotive quality management system international standard), consists of Three main phases such as planning, Implementation and sales. There are also five sub phases called “Planning”, “Product Design”, “Process Design and Development”, “Product and Process Verification and Validation”, and “Production”. These phases may be done concurrently and have correlated activities.

Our analysis shows that most of domestic researches about the new product development success factors are based on the Western literature and use them as the theoretical platform in the design of their own research strategy and research questions design. The paper proposes a contribution of measuring indicators extracted from literature review and completed by several industry and university experts’ interviews to finalizing the weighting indictors that could be useful in performance measuring on Auto new product development gates.


M.h. Shojaeefard, M. Manteghi, M. Hakimollahi,
Volume 6, Issue 4 (12-2016)
Abstract

New product development (NPD) is described in the literature as the transformation of a market opportunity into a product available for sale. In the automotive industry, within the context of ISO/TS16949:2002 (the automotive quality management system international standard),  these related to the product realization process (PRP) which consists of Three main phases such as planning, Implementation and sales, and  five sub-phases called  “Planning”, “Product Design”, “Process Design and Development”, “Product and Process Verification and Validation”, and “Production”. These phases could be done concurrently and have correlated activities.

 There has been a wide range of working in new product development but in automotive section no contributes has been done before. The paper proposes a contribution between the new product development performance factors of a same project in a developed country and developing country. It shows the differences of employee and systems ways of thinking in two above mentioned categories. The  main factors were extracted from literatures which are Goal clarity; Process formalization, Process Concurrency, Iteration, Learning, Team Leadership, Team Experience, Team Dedication, Internal Integration, External integration, Empowerment and Architecture. Having differences of people and systems thinking of new product development process of automotive engineering in two different working stations will be helpful in developing a complete model for performance measurement of a new product development in automotive industry. The questionnaires were made to analyze the value of each factor via employee view and system view and distribute in two different bases. The differences are illustrated in the paper.


M.h. Shojaeefard, P. Azarikhah, A. Qasemian,
Volume 7, Issue 2 (6-2017)
Abstract

Heat transfer in internal combustion engines is one of the most significant topics. Heat transfer may take place through thermal conduction and thermal convection in spark ignition engines. In this study, valve cover heat transfer and thermal balance of an air-cooled engine are investigated experimentally. The thermal balance analysis is a useful method to determine energy distribution and efficiency of internal combustion engines. In order to carry out experiments, a single cylinder, air-cooled, four-stroke gasoline engine is applied. The engine is installed on proper chassis and equipped with measuring instruments. Temperature of different points of valve cover and exhaust gases is measured with the assistance of K-type thermocouples. These experiments are conducted in various engine speeds. Regarding to the first law of thermodynamics, thermal balance is investigated and it is specified that about one-third of total fuel energy will be converted to effective power. It is also evaluated that for increasing brake power, fuel consumption will increase and it is impossible to prevent upward trends of wasted energies. In addition, it is resulted that, there is a reduction heat transfer to brake power ratio by increasing engine speed. Furthermore, it is found that, at higher engine speed, lower percentage of energy in form of heat transfer will be lost.
M. Hamidizadeh, M. Hoseini, M. Akhavan, H. Shojaeefard,
Volume 8, Issue 1 (3-2018)
Abstract

In order to achieve a successful new product, and certainly the successful implementation of a new product into a company, it is necessary to have a structured and documented approach to New Product Development (NPD), therefore providing a clear roadmap for the development of new products.New product development is a multi-stage process. Many different models with a varying number of stages have been proposed in the literature which in this paper are briefing them. This review highlights the NPD Models and process, from concept to consumer, and aim to find the consist gap of different NPD’s models in order for a company to succeed and use New products as a source for Competitive advantage.


Mohammad Hasan Shojaeefard, Azadeh Sajedin, Abolfazl Khalkhali,
Volume 8, Issue 4 (12-2018)
Abstract

Dual turbocharger turbine is fed by an unequal out-of-phase mass flow charge almost all the time which have significant effects on its performance parameters and flow phenomena which are not well known. Besides fully understanding the flow behavior in the radial turbine suffers from lack of detailed information about the secondary flows. This article studies the secondary flow structure within a dual entry turbine in different admission conditions. Results showed that with increasing the inequality of pressure ratio in the entries, performance of the turbine significantly decrease. From the results a profoundly disturbed flow in the interspace region was recognized. The pressure distribution of each limb shows some dependency between entries. To fully understand the flow physics, the 3D computational fluid dynamics (CFD) was implemented and compared with the experimental results of Copeland et al. (2010). The results are used to study the physical origin and the effect of nonuniform mass flow on secondary vortices. The generation and the development of the inflow, horseshoe and the corner vortex was investigated by evaluating contour plot of velocity distribution. Results demonstrated that the inflow vortex is due to the asymmetrical flow into the passage from the volute.

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