Additional Projects

Heat Sink Design & FEM Analysis in SolidWorks

I worked with two other students in my capstone thermofluid design course to model heat sink designs and evaluate their performance under different conditions using SolidWorks simulations. We first analyzed the chips' temperatures without heat sinks and with heat generation rates of 50, 30 and 20 W under natural convection conditions. Without heatsinks, the chips reached temperatures as high as 24,000 C and would burn up.

We designed heat sinks that were under designed, over-designed, and acceptable design. We then conducted simulations of the temperatures of the chips with the acceptable heat sink, under conditions of natural convection (h = 5 W/(m^2.K)), medium forced convection (h = 20 W/(m^2.K), and high forced convection (h = 65 W/(m^2.K)). The chips were only operable under conditions of high forced convection, where the hottest chip reached a maximum temperature of 82 C. Under transient conditions, we found that the system becomes steady-state at 8 minutes.

Link to Report

Heat Exchanger Design for Pasteurization

In a team of three, I helped design a HTST (high temperature short time) heat exchanger for pasteurization with a 20,000 Liter/hr flow rate of the milk. We designed four separate heat exchangers, determining the flow rates, interface-surface area, and rate of heat transfer for each one. We used counterflow, shell and tube heat exchangers. We calculated the number of tubes, the necessary pipe dimensions, and estimated the pump power needed for each heat exchanger as well as the overall design. For instance, a sample calculation for the "chiller" heat exchanger is shown to the right. Milk will enter the chiller at 47 C and leave at 35 C. This heat exchanger will cool the milk using cold water at 30 C. Heat Exchanger #3 will have 160, 1" diameter tubes made of food grade Stainless Steel as standard in the pasteurization industry. These tubes will be approximately 1 m in length. The tubes will be arranged in a single pass, counter flow Tube and Shell exchanger design, as shown below in Figure 3.3.1. Baffles will be added to encourage turbulent mixing and a higher overall heat transfer coefficient.

We provided a complete system diagram of the heat exchangers, shown to the right. This diagram includes temperature and flow sensors placed at the inlet and outlet of each heat exchanger to effectively monitor and control the system.

We also performed an approximate energy-based cost analysis of the system, as well as a yearly cost saving analysis by using the "Regenerator" heat exchanger which uses previously heated fluid to warm incoming milk. With an energy cost of $0.15 kW/hr, the regenerator saves $89.58/hr.

Link to Report

Home Energy Consumption Analysis Using BEOpt

I worked in a group of three to explore energy efficiency for a house design using BEOpt (Building Energy Optimization Tool). BEOpt is a software tool developed by the National Renewable Energy Laboratory that allows for the evaluation and optimization of residential building designs to identify cost-optimal efficiency packages at various levels of whole-house energy savings. We analyzed designs of two different houses, one based on a cottage-style design, and one based on a colonial design.

We performed a parametric study of how energy usage is affected by house location, insulation R-Value, roof material, lighting, and different window U-values. The insulation R-values tested ranged from R-7 to R-21. The roof materials analyzed were asphalt shingles, tile, and metal. Window U-values were tested from 0.17 to 0.76, with 0.17 being the most efficient. The lighting was compared between incandescent, CFL, and LED, with LED being the most efficient. All other input parameters offered in BeOpt were held constant between the initial and revised designs.

The results of the BEopt simulation and analysis indicated that the R-value and window U-value are two key input parameters that have the most significant impact on the source energy usage of a house. Therefore, prioritizing upgrades or modifications in these areas can yield energy savings. Improving lighting to 100% LED also significantly reduced electricity usage and is a cost-effective and easy home upgrade.

Exhaust System for Customer Prototype

During my internship with Columbia Tech, I collaborated with another intern to design and implement an exhaust system for a large scale customer prototype that was being tested indoors. The system cost close to $1000 and spanned 120 feet. It was successfully assembled and implemented for the customer's test.

Me and the fellow intern also built a pneumatic tubing system for the same prototype. The customer's product is not on the market yet, so I am withholding specific information about their product and how it works.

Stirling Engine

This past spring, I took a manufacturing course where we learned how to operate mills and lathes. We also learned how to run and debug CAM software. As the final project for the class, I constructed a stirling engine, using mills and lathes to make each component.

As with any standard engine, a stirling engine runs through a cycle of cooling, compression, heating and expansion. For stirling engines, this process is triggered by the cyclic compression of air. The engine has a sealed cylinder with one part hot and the other part cold. Our engines were started by lighting a string coated in oil on fire, which heated the steel wool within the cylindrical chamber above.

Op-Amp Circuit

Last spring, I took a 2000 level Electrical and Computer Engineering course. In the course, we covered topics such as AC/DC circuits, linear circuit simulation and analysis, op-amp circuits, transducers, feedback, circuit equivalents and system models, and digital logic gates.

We had laboratory classes twice per week, where we built different circuits using the material covered in class the week prior. Shown to the right is a circuit that my lab partner and I built that contains an operational amplifier (op amp). Op-amps are used to amplify the voltage between two inputs. We used voltmeters and ammeters to measure voltage and current at different points in the circuit, and compared our measured values to the theoretically calculated values to make sure our circuit was built correctly.

Custom Calculator Case

I designed this TI-84+ calculator case from scratch and printed it on my own Ender 3 Pro 3D printer. The measurements of the case needed to be very precise in order to fit the calculator snugly. I printed several iterations of different parts of the case before printing a full model.

This case has my name and a WPI goat logo, which I transferred from InkScape as an svg file. The exterior design on the case can easily be adjusted, and I've printed custom cases for my friends who have their own TI-84+ calculators.

Flippable Bench

Designed in SolidWorks, this bench has seats which can be rotated to face either direction. This creates privacy, and the support for each seat also doubles as a side table for somebody sitting adjacent and facing the reverse direction.

The image to the left is a rendering of the current design. I haven't made a physical model of the bench yet, and more adjustments may be needed, such as simplifying the table design and increasing the strength of the bench's foundation, which I plan to test using SolidWorks simulations.