Mehmet Sozen - Academia.edu (original) (raw)

Papers by Mehmet Sozen

This paper presents an analysis for the forced convective flow of a gas through Introduction Pack... more This paper presents an analysis for the forced convective flow of a gas through Introduction Packed beds have been used very widely in the chemical industry and for energy storage purposes. Among the common applications are catalytic reactors, absorption and adsorption operations, as well as packed bed (pebble bed or rock pile) heat storage units. Due to their high performance, they are now also being considered for use in a number of applications such as fixed-bed nuclear propulsion systems and spacecraft thermal management systems. Utilization of phase-change material in microencapsulated form as the solid particles of the bed has also proved to be a promising research area. For example, A major part of the studies conducted to date on packed bed applications concentrate on utilizing incompressible fluids, liquid or gas, as the heat transfer medium. In these investigations a constant mass flow rate is assumed at every cross section of the packed bed and therefore there is no need ...

Volume 7: Engineering Education and Professional Development, 2009

With the increased interest and focus on sustainability and energy independence, utilization of r... more With the increased interest and focus on sustainability and energy independence, utilization of renewable energy resources has been receiving a lot of attention. A new course on Alternative and Renewable Energy has been developed in the School of Engineering at Grand Valley State University as both a new technical elective course in thermofluids area as well as an alternative to the existing Combustion Applications course. While this course emphasizes alternative and renewable energy sources and applications, it also encompasses the basics of combustion of hydrocarbon fuels that is not covered in the single compulsory four credit hour thermodynamics course in the mechanical engineering curriculum. In this sense it serves a unique purpose of filling in an important gap in the curriculum. The laboratory used for the combustion course has been enhanced and transformed to be a Combustion and Energy Applications Laboratory. The experimental course that was developed and offered for the f...

Volume 5: Engineering Education and Professional Development, 2011

In the use of solar energy as a source of renewable energy a practical question is commonly encou... more In the use of solar energy as a source of renewable energy a practical question is commonly encountered. “What is the optimal angle of inclination for fixed solar panels?” This is applicable for both arrays of solar photovoltaic (PV) panels as well as for flat plate solar collectors. It is quite common practice to use a couple of rules of thumb that state the following: (a) the panels/collectors should be facing south (for the northern hemisphere locations), and (b) the optimal angle of inclination will be in the range of the location latitude ± 15°. In this paper we discuss a computer program developed to verify (b) for south facing fixed solar panels/collectors. The program developed can generate theoretical solar irradiation that will be available for a given location in the northern hemisphere on a clear day taking into account the attenuation effects in the atmosphere by incorporating the concept of air mass. It can also be used to retrieve solar irradiation data from well established databases such as the National Solar Radiation Data Base (NSRDB) [1–2] accessible via the National Renewable Energy Laboratory (NREL). Both approaches have been tested and weekly, monthly and annual optimal angles of inclination have been generated for selected locations. This paper discusses the details of the algorithm and code developed and the results obtained. How this program is going to be used in an undergraduate course titled “Alternative Energy Systems and Applications” are also discussed.Copyright © 2011 by ASME

Due to shortages in renewable energy resources, solar photovoltaic panels and solar thermal colle... more Due to shortages in renewable energy resources, solar photovoltaic panels and solar thermal collectors have been widely researched and continue to be installed on commercial and residential buildings in order to reduce greenhouse gas emissions. Improvements in the efficiencies of photovoltaic panels are on the rise, making their use more feasible in more geographic locations. However, the angle at which the panels are mounted (angle of inclination or slope angle) can also significantly affect the solar irradiation they receive. The theoretical optimal angle of inclination of these panels has been determined based on the extraterrestrial solar constant, the effect of air mass, and assumption of clear skies. However, the assumption of clear skies may lead to significant discrepancies between theoretical model predictions and otherwise available meteorological data. Therefore, this paper aims to determine whether the optimal angle of inclination of solar photovoltaic panels will differ...

A mathematical model was developed for simulating the transport phenomena in a porous cooling cha... more A mathematical model was developed for simulating the transport phenomena in a porous cooling channel and the conjugate heat transfer in the surrounding wall. The numerical solution by the use of variable grid finite difference method was implemented by using MATLAB computing environment, a fourth generation programming language. Several case studies performed showed the behavior of the flow field in the porous cooling channel and the temperature distribution in the two domains of the problem. The use of MATLAB computing environment was shown to have several major advantages over the use of third generation programming languages such as FORTRAN and C. It was observed that when a numerical method involving extensive matrix operations was chosen, the built-in functions in MATLAB made the solution much simpler, requiring considerably less math background and programming efforts/skills. MATLAB also offered easy to use post-processing tools not available with other

Volume 2: Reliability, Availability and Maintainability (RAM); Plant Systems, Structures, Components and Materials Issues; Simple and Combined Cycles; Advanced Energy Systems and Renewables (Wind, Solar and Geothermal); Energy Water Nexus; Thermal Hydraulics and CFD; Nuclear Plant Design, Licensi..., 2013

International Journal of Heat and Mass Transfer, 1990

In this paper, the transient forced convective condensing flow of a gas through a packed bed is a... more In this paper, the transient forced convective condensing flow of a gas through a packed bed is analyzed. The model developed for this analysis does not employ any local thermal equilibrium assumption between the solid and the fluid phases. Inertial as well as viscous effects are considered in the vapor phase momentum equation by using the Ergun-Forchheimer relation. Thermal charging of the packed bed for two different types of boundary conditions and the condensation in the vapor phase are studied. Qualitative comparisons of the effects of different parameters on condensation reveal that the pressure difference applied across the packed bed, the particle size of the solid phase, and the heat capacity of the solid phase are very influential on condensation. It is observed that although two-dimensional modeling is essential for accurate results in the case of constant wall temperature boundary conditions, one.dimensional modeling would be quite satisfactory in the case of insulated boundary conditions.

39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 2003

The Generalized Fluid System Simulation Program [ 11 (GFSSP) is a computer code developed at NASA... more The Generalized Fluid System Simulation Program [ 11 (GFSSP) is a computer code developed at NASA Marshall Space Flight Center for analyzing steady state and transient flow rates, pressures, temperatures, and concentrations in a complex flow network. The code, which performs system level simulation, can handle compressible and incompressible flows as well as phase change and mixture thermodynamics. Thermodynamic and thermophysical property programs, GASP, WASP and GASPAK provide the necessary data for fluids such as helium, methane, neon, nitrogen, carbon monoxide, oxygen, argon, carbon dioxide, fluorine, hydrogen, water, a hydrogen, isobutane, butane, deuterium, ethane, ethylene, hydrogen sulfide, krypton, propane, xenon, several refrigerants, nitrogen trifluoride and ammonia. The program which was developed out of need for an easy to use system level simulation tool for complex flow networks, has been used for the following purposes to name a few:

2005 Annual Conference Proceedings

The paper discusses the implementation of a unified approach for solving combustion problems by a... more The paper discusses the implementation of a unified approach for solving combustion problems by applying the first and second laws of thermodynamics simultaneously with applications for the classroom. The model was developed for the combustion of hydrogen and oxygen using ideal gas mixture assumption for the reactants and combustion products, and was based on chemical equilibrium assumption. The authors implemented the second law (minimization of Gibbs free energy) in two different but equivalent methods: one used chemical equilibrium constants as functions of temperature correlated from data tables, and the other computed the equilibrium constants using the change in Gibbs free energy computed from elementary thermodynamic properties. The latter method was implemented using MathCad for the solution of the problem. Solutions were obtained for fuel to oxygen ratios covering fuel rich to fuel lean conditions. These solutions were compared with those obtained using a FORTRAN code based on the first approach and originally reported by Sözen and Majumdar [1] at the 2004 ASEE Annual Conference. Excellent agreement was found between the two solution methods. It was demonstrated that MathCad provides a powerful tool in implementing this approach to the solution of combustion problems for use in a course in thermodynamics, at the undergraduate level, or in an introductory course in the theory of combustion. The paper reports classroom experience using the MathCad model as a teaching/learning tool to teach combustion in a second semester thermodynamics course taught in the Fall of 2004.

2013 ASEE Annual Conference & Exposition Proceedings

A course about alternative energy systems and applications was developed and has been taught for ... more A course about alternative energy systems and applications was developed and has been taught for the past four years at Grand Valley State University. The course, which has been taught as a four credit hour technical elective course in engineering, has been offered in various formats, such as simply a four contact hour course and most recently formalized as a three-lecture threelab-hours format. Invariably though, the course involved case studies and semester projects. These projects have been mostly about feasibility studies on applications of such energy resources to real world problems. Several software tools have been acquired and implemented for simulation and analysis. These include such programs as PV f-Chart, f-Chart, and TRNSYS as well as Idaho National Laboratory's Wind Energy Analysis Program, which are being used in the enhancement of student training and learning in the course. This paper discusses the use of such tools in satisfying the objectives of the course and the assessment of the use of such tools from the instructor and student point of view.

2011 ASEE Annual Conference & Exposition Proceedings

is an associate professor of engineering at Grand Valley State University. He teaches in the area... more is an associate professor of engineering at Grand Valley State University. He teaches in the area of thermofluid sciences and energy related courses. His specialty and interest include transport phenomena in porous media, combustion, thermal management, high heat flux applications and alternative and renewable energy applications. David Faasse David is a graduate of the University of Michigan with a Bachelors degree in Aerospace Engineering. Former graduate student of the the School of Engineering at Grand Valley State University.

44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2008

Volume 6: Engineering Education and Professional Development, 2010

Energy, environmental issues and society awareness are three of the main components in many engin... more Energy, environmental issues and society awareness are three of the main components in many engineering problems. Engineering Schools use general education courses to address these issues. However, the bridge between the engineering skills and these issues is still a challenge. In the present work, an open-ended design project was used in a senior level Heat Transfer course to address this need. The students were asked to work in teams to design and build a one- or two-person shelter that is built from recycling material and has no active heat source. The shelter should be portable and easily assembled and disassembled using limited tools to match the use in the time of crises or in developing countries. The details of the project are presented and supported by samples from the students’ work.

Annual Review of Heat Transfer, 1990

ABSTRACT This chapter presents a critical review and comparison of a carefully selected set of mo... more ABSTRACT This chapter presents a critical review and comparison of a carefully selected set of models for heat and mass transfer in the presence of phase change in porous media. The selected models represent the most generally applicable classical models of this subject. This study examines the details of the transport phenomena and the relevant terms appearing in each model and makes qualitative comparisons among the models. It poses the main assumptions and the consecutive simplifications employed in each model. It is ...

Journal of Thermophysics and Heat Transfer, 1991

Abstract The thermal-energy storage characteristics are examined analytically with respect to pac... more Abstract The thermal-energy storage characteristics are examined analytically with respect to packed beds from both sensible heat storage and latent heat storage. The thermophysical properties of Refrigerant-12 are assumed and modeled for an ideal gas, and inertia effects are considered in the vapor-phase momentum equation. The two packed beds show distinct energy-storage characteristics: the total energy-storage capacity of the latent model is higher, and the thermal charging and discharging times in the latent model differ ...

Journal of Thermophysics and Heat Transfer, 1993

Abstract The forced convective flow of a slightly superheated vapor through a packed bed is analy... more Abstract The forced convective flow of a slightly superheated vapor through a packed bed is analyzed numerically for low-to-moderate pressure range by implementing real-gas and ideal-gas models. The porous bed was taken to be composed of uniformly sized, randomly packed spherical particles. The flow of the gas through the packed bed was limited to the range of applicability of the Ergun-Forchheimer relation. The significance of longitudinal thermal dispersion was examined by alternately implementing and omitting this aspect ...