Reed Brown

Systems Engineer at Raytheon IDS


Research – Interface Decohesion

In September 2018, I began a research project with Professor Kyung-Suk Kim at Brown University, whose lab studies the mechanical properties of bimaterial systems, such as the polymer polyurea bonded to a steel substrate. Such bimaterials can have extremely high strength under high strain rate conditions and are often used for blast protection. My project focused on the cohesive behavior – the bond along the interface of the two materials – of the bimaterial system. My lab had the ability to gather interferometry data (related to surface displacement) during high-speed plate impacts of bimaterial samples. However, one cannot determine the cohesive behavior, specifically the traction-separation law (TSL) parameters, from this data alone; simulated data is also required. I designed an Abaqus simulation of the experiment with a guess for the TSL parameters. If the guess produces simulated data that is very similar to the experimental data, then the guess must be very close to the true TSL parameters. Based on this concept, I then assembled a software package that integrated Abaqus’ simulation features with MATLAB’s optimization tools to iteratively test different TSL parameters until convergence between simulated and experimental data is achieved. I presented my work at an end-of-year symposium as well as a written thesis, for which I was awarded Honors at graduation. Click the links below to learn more!

Research – Model Turbine Generator

In September 2017, I began a research project with Professor Shreyas Mandre at Brown University, to analyze the effect of turbine placement on the efficiency of turbine arrays. With access to a small wind tunnel, and the ability to 3D print towers and rotors, my partner and I soon realized that our biggest obstacle would be measuring the power output of an individual turbine. Following a literature review, we settled on using calibrated DC motors, driven in reverse, as generators on the model turbines. Using a specially designed calibration setup, the motors were calibrated between torque, electrical current, and rotation rate. With rotation rate’s being comparatively easy to measure, our successful calibration allowed us to measure, with minimal interference to the flow and with relative ease and accuracy, the power output of model wind turbines, simply by measuring the electrical signal from the motor. We presented our methodology and results at a Brown University poster symposium. Click the link below to view the poster!


Internship – DDMotion

In the summer of 2017, I interned at a small engineering company called Differential Dynamics Corporation. The company has developed a proprietary gear assembly that converts a variable speed input to a constant speed output by using a constant speed control input. This technology has applications to the wind and hydrokinetic turbine industries, in which the inherent variability of natural fluid motion can be problematic in generating grid-compatible (constant frequency) electricity. I and a partner built a demonstration model of the assembly, and then analyzed the kinematic relations as well as the power flow from input to output (using a custom-built rope brake dynamometer). Click the link below to read our paper describing the analysis and experimentation!