Project Description: 

Frost formation in heat pump fin surfaces during cold climate conditions can significantly degrade the performance of air-source heat pumps. Typical thermal defrosting methods are energetically expensive and can cause thermal discomfort. This research investigates a novel mechanical defrosting solution for heat exchanger fins using multistable shape morphing cells integrated into the fins. Metal working is used to manufacture fins exhibiting multistable behavior (bistable and metastable) by plastically deforming selective regions of a laser-cut flat fin precursor. These structures undergo snap-through and suddenly release energy upon actuation, the induced out-of-plane displacements and vibrations can be used to break and shed frost. The mechanical defrosting approach on average consumes 81.09 less energy, requires 10.84 times less power and is 8.26 times faster. ​

The mechanical defrosting is highly effective for solid frost. The highly ductile nature of porous frost requires conversion to solid frost which can then be shed using a thermo-mechanical defrosting strategy.

In this project I led the product development cycle from concept to Technology Readiness Level 3. We secured several grants from Center for High Performance Buildings (CHPB) and collaborated with industry professionals to ensure design for manufacturability and assembly (DFMA). This research led to a utility patent (US20230015420A1). ·

Project Description: 

This project explores the nonlinear dynamics of phase transformations in multistable cellular structures (PXCM). These structures exhibit frequency up-conversion, a process by which low and ultra-low frequency input displacements are transformed into high-frequency oscillations. These oscillations are subsequently converted into electrical energy using piezoelectric attachments. This energy conversion enables the structures to exhibit multifunctional capabilities of energy absorption and energy harvesting. The harvested energy can be utilized to power low-power condition monitoring and IoT sensors, which can be employed in various applications, including infrastructure monitoring, environmental sensing, and smart devices.

Project Description: 

• Conducted numerical simulations and experiments on wave dynamics and modal analysis of granular materials.

• Leveraged vibrational analysis, test fixture design, signal processing, 3D printing, and CAD/CAM to realize topological band transition in granular crystals.

Publications:

• R. Chaunsali, E. Kim, A. Thakkar, P. G. Kevrekidis, J. Yang. Demonstrating an in situ topological band transition in granular crystals. Physical Review Letters 119, 024301, 2017. pdf 

Project Description: 

In this project we investigate the effects of various aging treatments/single aging and duplex aging on the mechanical properties of metastable beta titanium alloy (Ti-15-3). We performed microstructural analysis (XRD, SEM, and optical micrographs) and mechanical testing (tensile strength, hardness, and impact toughness) to derive microstructure-property-processing relationships.

Publications:

• A. Thakkar, R. Santhosh , M. Geetha, M. Nageswararao. Isochronal aging studies on beta titanium alloy Ti-15V-3Cr-3Al-3Sn. 2016. pdf

Project Description: 

• Designed, engineered and manufactured a three-wheeler prototype car that runs on gasoline with an aim to maximize its fuel efficiency.

• Led the team to a successful conceptualization and fabrication of a customized steering system.

• Designed, CAD modeled, and conducted FEA, CFD and thermal analysis on various mechanical components using Solidworks and ANSYS.

• Manufactured and fabricated various components using Lathe, milling, drilling and other mechanical operations.