Master of Science in Mechanical Engineering, Cleveland State University, 2015, Washkewicz College of Engineering

Design of the fluid flow and heat transfer components utilizing the Computational Fluid Dynamics (CFD) is relatively new yet cheaper and accurate method that becomes popular and reliable today. In this thesis, design of a heat exchanger using CFD analysis technique is considered. A key investigation of this devise is the selection of the tubes and connection them to inlet and outlet manifolds. Correctly selected tube size and tube cross section impacts the heat exchanger performance. Thermal and hydrodynamic performance of the flow in circular and elliptic tubes connected to the inlet and outlet manifolds have been computationally investigated for maximum Figure of Merit. The tube with high Figure of Merit is the one with high heat transfer rate and low pressure drop. The tube has four different configurations of the cross section: a circular tube and three elliptic tubes with aspect ratios = 0.75, 0.50, and 0.25. All tubes are constrained to have the same wetted perimeter and the length, thus have the same heat transfer area. The tube is a smooth straight tube that has the length of 0.3048 m (12 in.) and wetted perimeter of 0.0798 m (3.1416 in.). The tube wall thickness is negligible. The contribution of the inlet and outlet manifolds is examined. A wide range of Reynolds numbers is covered, Re =100 (laminar flow), 10,000 (transitional flow), and 20,000 (turbulent flow). ANSYS FLUENT commercial code has been utilized in this investigation. The code was validated matching with experimental correlations (for developing hydrodynamic and thermal flow) available in the literature. The CFD simulation results were in agreement with the experimental correlation within 5%. This investigation started with simulating 12 different flow conditions inside the tubes without manifolds: three sets with four different tube options (as stated above) in each set. Each set represents the different flow regime: laminar transitional and turbulent with set Reynold number value, as n (open full item for complete abstract)

Committee: Mounir Ibrahim PhD (Committee Chair); Majid Rashidi PhD (Committee Member); Asuquo Ebiana PhD (Committee Member) Subjects: Aerospace Engineering; Automotive Engineering; Mechanical Engineering; Nuclear Engineering; Petroleum Engineering

MS, University of Cincinnati, 2009, Engineering : Mechanical Engineering

Experiments were performed on a heat exchanger equipped with multiple thermoelectric (TE) modules. The primary objective was to design a simple, but effective, modular Peltier heat pump system component to provide chilled or hot water for domestic use. Moreover, the modular design of this system component is such that the total system capacity is scalable such that it can potentially be used for hydronic building climate control of small solar residences, where the TE devices could be directly energized using solar powered PV panels, and coupled with the building inlet water supply heat sink and grey water heat recovery, providing a renewable, pollution free and cost-effective solutions to the home energy problem. First, the work focuses on the design and testing of a thermoelectric heat exchanger component that consists of two water channels machined from two aluminum plates with an array of three or five thermoelectric modules placed in between to cool and/or heat the water. Then the work focuses on the detailed convection analysis inside the TE-HX component when 10 thermoelectric modules are utilized. The local heat transfer coefficient at different points along the channel are measured at steady-state, first, when a continuous heater is installed and then when replaced with 10 TE modules. The experimental heat transfer coefficients obtained are compared with available empirical correlations for developing “transition” (3000 < ReDh < 7000) turbulent flow inside the channel with fair-to-good results. Next, the resulting coefficient-of-performance of the TE heat pump system is measured with its value depending both on system input power and water flow rate. Testing showed that performance degradation, i.e. reduced COPs, occurred when operated at higher power levels but remains satisfactory for up to 688 Watts with higher flow rate. A comparison of the system performance with different TE module arrangements at different power level has also been made which gives th (open full item for complete abstract)

Committee: Dr. Michael Kazmierczak PhD (Committee Chair); Dr. Milind A. Jog PhD (Committee Member); Dr. Sang Y. Son PhD (Committee Member) Subjects: Mechanical Engineering