Category: Research

Mehendale Publishes on Metal Foams

Journal of Heat Transfer

A research paper by Sunil Mehendale (MMET), has been accepted for publication in the American Society of Mechanical Engineers (ASME) Journal of Heat Transfer (JHT), a top-notch journal that disseminates information of permanent interest in the areas of heat and mass transfer.

The journal is reputed for its rigorous peer review process and there is a general consensus that the JHT is the world’s premier journal in its field. The paper, “Thermal-Hydraulic Optimization of Open Cell Metallic Foams Used as Extended Surfaces,” has been posted online and is available in the Accepted Manuscript section of the journal on the ASME Digital Collection.

Article Summary

Heat transfer and fluid flow in metal foams is encountered in a broad range of natural and industrial processes which includes such diverse fields as compact heat exchangers, fuel cell technology, filtration, and physiological processes. An analytical validated model for predicting temperature distribution, heat transfer, pressure drop, and fluid pumping power in an open-cell metal foam fin is developed. A foam length optimization technique based on its performance factor (PF) is proposed. An often-used fin optimization criterion recommends that the fin effectiveness should equal or exceed 2. The present study shows that the effectiveness of any optimized foam always exceeds 2. However, the converse, i.e., requiring the foam effectiveness to at least equal 2, does not guarantee an optimal foam, which implies that the PF-based optimization criterion is an inclusive one. It is also proved that a previously suggested optimization criterion of maximizing a foam’s geometric mean efficiency will result in a sub-optimal foam design.

https://doi.org/10.1115/1.4050921


Mehendale and Warty Co-author Paper on Energy Modeling

High Performance Buildings

Sunil Mehendale (MMET) co-authored, with graduate student in ME-EM Amarnath Warty, the peer-reviewed paper “Energy Modeling and Energy Efficiency Opportunities for a Public Library Building in the Upper Peninsula of Michigan.” 

The paper has been accepted for publication and presentation at the 2021 Purdue High Performance Buildings conference.

Brief description of research: The present research has a twofold aim: (1) to model the natural gas consumption and the total electricity consumption of a 12600 sq. ft. public library building in Houghton, MI, and (2) to identify any opportunities to improve energy efficiency. This was accomplished by first developing and validating an eQUEST model for the library building in conjunction with a linear regression model correlating the natural gas consumption (during winter) with heating degree days and the electricity consumption (during summer) as a function of cooling degree days. The said library building, which is serviced by two rooftop furnaces, each with a DX coil, and a hot-water loop using two boilers, has been facing HVAC issues for a few years now, the most common complaint being that it gets too hot in the winter despite the thermostat being set to provide comfortable temperatures. Preliminary results suggest that the principal factors affecting the building energy consumption are the HVAC loads, lighting, and occupancy and that the natural gas consumption of the building could be lowered by up to 20% using the furnace units alone (i.e., by dispensing with the boilers), while still meeting the building’s heating requirements.


Mehendale Publishes on Heat Exchanger Project

Sunil S. Mehendale
Sunil S. Mehendale

Sunil Mehendale (MMET) co-authored the article, “The influence of Header Design on Two-Phase Flow Distribution in Plate-Fin Heat Exchangers”, which has been accepted for publication in the ASME’s (American Society of Mechanical Engineers) Journal of Thermal Science and Engineering Applications.

This paper experimentally demonstrates that improved heat exchanger header designs through the use of carefully designed perforated plates placed prior to the entry of fluid into the heat exchanger can significantly aid in distributing the two-phase flow more evenly. Thereby, any degradation in the thermal-hydraulic performance of the equipment stemming from flow maldistribution can be effectively minimized.


Sunil Mehendale Comments on Geothermal Systems

Sunil S. Mehendale
Sunil S. Mehendale

A modern remix of old technologies that cuts home energy bills has the potential to utterly transform homes in the future, and the system was created in East Tennessee’s own Oak Ridge National Lab.

Scientists have developed prototype geothermal “batteries” that, unlike conventional batteries, actually tap and store the heat energy of the Earth to provide heating, cooling and hot water.

Phase change materials have been in use for at least a decade in diverse applications, from medical care to home climate control.

“None of these technologies themselves are new,” said Sunil Mehendale, associate professor of mechanical engineering at Michigan Tech. “But combining all these technologies together in one structure, that’s what brings the novelty.”

“I would really like to see how a full-scale device stacks up against current technology,” Mehendale added.

Read more at Knoxville News Sentinel, by Vincent Gabrielle.