Mechanical Engineeringhttp://hdl.handle.net/10211.3/1799682019-06-18T17:04:41Z2019-06-18T17:04:41ZCharacterization of a Photovoltaic SystemYassine, Waelhttp://hdl.handle.net/10211.3/2066152018-11-10T00:27:55Z2018-11-09T00:00:00ZCharacterization of a Photovoltaic System
Yassine, Wael
The purpose of this project is to obtain a characteristic equation for the power transfer between a photovoltaic system and the battery (or batteries) being charged. In most applications, a charge controller is used to regulate the power input into the battery and protect it from overcharging. The relation between the power output from the solar panels and power input to the battery is the goal of this project. This relation is defined by the
Transfer Function between the solar panels and battery. The charge controller is treated as a black box; hence no analysis of its internal circuit will be done. Once the Transfer Function is determined, it will be possible to predict the power input into a system of batteries from a given system of solar panels.
2018-11-09T00:00:00ZAnalytical and Numerical Studies of Nanofluid Heat PipesYazdanpanah, Babakhttp://hdl.handle.net/10211.3/2065542018-11-06T21:51:33Z2018-11-06T00:00:00ZAnalytical and Numerical Studies of Nanofluid Heat Pipes
Yazdanpanah, Babak
In this thesis, numerical and analytical studies of the rectangular and disk-shaped nanofluid heat pipes are performed. The effect of using nanofluid on the heat pipe performance has been evaluated through the velocity, pressure, and temperature profiles. The results show the existence of an optimum concentration of nano particles within the working fluid to enhance the thermal performance of the heat pipe. The modeling results show a good degree of compatibility with the published literature.
2018-11-06T00:00:00ZAn Investigation of Semi-Monocoque Aircraft Structural Design With a Detailed Evaluation of Primary Structure Member Stability CriterionSaeed, Isaachttp://hdl.handle.net/10211.3/2065182018-10-26T22:37:44Z2018-10-25T00:00:00ZAn Investigation of Semi-Monocoque Aircraft Structural Design With a Detailed Evaluation of Primary Structure Member Stability Criterion
Saeed, Isaac
The paper presented here has been developed by Isaac Saeed for the purpose of fulfillment of the requirements for the acquisition of a Master of Science Mechanical Engineering degree, issued from California State Polytechnic University, Pomona in 2017.
This thesis investigates the fundamental classical methods used in the structural analysis of semi-monocoque aircraft which are currently used by the aerospace industry, summarizing their usage and evaluating their performance in accurately characterizing primary stress values as compared to a coarse mesh FEM analysis. The fast-paced nature of the aerospace industry requires a balance to be struck between speed and accuracy when selecting an appropriate method of analysis for primary structure. The selection of a suitable approach must take into consideration the time, complexity & cost associated with any evaluation. Often a decision is made between the implementation of classical hand analysis methods and a more complex Finite Element Analysis. Computer simulations are often utilized in an effort to achieve greater accuracy and resolution verses classical methods. Finite Element Analysis offers an excellent way to characterize an accurate set of stresses. However, it is widely understood that it should not completely replace simple classical hand analysis, which can be used in preliminary design, repairs, and even for complete structural analysis in many cases.
The structural response of lightweight structures like aircraft is dominated by the stability of members and substructures. Methods to characterize structural member stability have been the focus of numerous theoretical and experimental investigations over the past century. Although Finite Element Models have the ability to accurately predict the structural behavior of structures, they must be extremely detailed to capture all of the effects of stability. A complete departure from classical hand analysis in favor of FEA is inefficient, and usually falls short of a complete characterization of the structural response. Therefore, a detailed classical analysis should precede most FEA work. It has been proposed that a coarse mesh FEM that produces localized internal loads, followed by classical analysis of individual elements is a more effective way to capture both the enhanced accuracy of Finite Element Methods along with the semi-empirical findings of classical methods.
These ideas are illustrated by implementing this approach on a sample structure. A geometry representative of typical semi-monocoque aircraft structure is established and used as an example for select calculations. Classical methods are used to develop representative member geometries which incorporate the nonlinear effects of stability. These static geometries are then applied to a coarse mesh FEM in order to achieve a quasi-nonlinear structural evaluation of the structure as a whole using a linear static (Solution 101) solution method.
A brief comparison is then made between a pure classical method approach and the coarse mesh FEA approach in order to show convergence of the two methods when applied to the sample structure. The correlation between these results allows for this combined approach of classical hand analysis and Finite Element analysis to be implemented to a more complex geometry with an increased level of confidence.
2018-10-25T00:00:00ZCFD Analysis of a Two Stroke Combustion EngineMendez, Christianhttp://hdl.handle.net/10211.3/2058222018-08-27T20:27:56Z2018-08-27T00:00:00ZCFD Analysis of a Two Stroke Combustion Engine
Mendez, Christian
A Computational Fluid Dynamics analysis of a Lightweight High Specific Power Two-Stroke Polygon Engine will be presented in this report. The 2D analysis will focus on the combustion occurring within the engine’s chamber. The report will detail the chamber dimensions, mesh, governing equations, fluid properties, boundary conditions, and output results for the premixed combustion simulation. Results will include interpolation of bar charts and visual illustrations such as contour plots, vector plots, and streamlines for various fuels. The premixed combustion model will also showcase the development of the combustion through four piston positions going from Top Dead Center to Bottom Dead Center. The initial set of results gave rise to an interesting insight of the premixed combustion model, which led to produce another set of results for a different inlet velocity. The results for the two different inlet velocities will be compared and analyzed to show the effect on the output results from the change in velocity.
2018-08-27T00:00:00Z