Statewide Users Group Conference Minutes - April 18, 2019

Thursday, April 18^th 

Keynote Address
Santosh Rao, Senior Technical Director of NetApp

Santosh Rao is responsible for NetApp’s AI and data engineering products and solutions business. He works closely with the AI solution ecosystem across GPU, compute, software, consulting and channel partners as well as customers worldwide. He is a regular speaker at various events and writes a blog on the data pipeline for AI.

He has held a number of roles within NetApp and led the original ground-up development of Clustered ONTAP SAN for enterprise workloads. Over the years, he has led to market a number of follow-on products for NetApp involving data migration, virtualization, distributed systems, management by SLO, application integration and most recently, all flash SAN technologies, NoSQL and big data solutions.

Prior to joining NetApp, Santosh was a Master Technologist for HP and led the development of a number of storage and operating system technologies for HP including the development of their first generation products for a variety of storage and OS technologies over the years.

Committee Reports

Allocations Committee

Software and Activities Committee

Hardware and Operations Committee

Flash Talk Winner

Arif Hossain, Graduate Research Associate at The Ohio State University
"Sweeping Jet Film Cooling and Impingement Cooling for Gas Turbine Heat Transfer Application"
Due to the increased freedom in additive manufacturing, the complex internal and external geometries of the turbine blade can be leveraged to utilize innovative cooling designs to address some of the shortcomings of current cooling technologies. The sweeping jet film cooling has shown some promise to be an effective method of cooling where the coolant can be brought very close to the blade surface due to its sweeping nature. A series of experiments and numerical calculations were performed using a fluidic oscillator that can generate an oscillating jet without any moving parts. Adiabatic cooling effectiveness, convective heat transfer coefficient, thermal field, and discharge coefficient were estimated over a range of blowing ratios and freestream turbulence using computational fluid dynamics (CFD). Results were compared with a conventionally shaped hole (777-hole) and the sweeping jet hole shows improved cooling performance in the lateral direction. Large Eddy Simulation (LES) and Unsteady RANS (URAN) calculations confirmed that the sweeping jet creates two alternating vorticies that do not have mutual interaction in time. When the jet sweeps to one side of the hole exit, it acts as a vortex generator as it interacts with the mainstream flow. This prevents the formation of the counter-rotating vortex pair (CRVP) and allows the coolant to spread in the lateral direction. The results obtained from the CFD were utilized to design the sweeping jet film cooling hole for more representative turbine vane geometry. Experiments were performed in a low-speed linear cascade and a high-speed transonic cascade facility. Results showed that the sweeping jet hole has higher cooling effectiveness in the near hole region compared to the shaped hole at high blowing ratios. 
Spatial uniformity is identified as a major issue for impingement cooling at the leading edge of the turbine blade which can be significantly improved by sweeping jet impingement cooling. A series of numerical simulations were also performed with a fluidic oscillator for impingement cooling on a flat surface and a curved surface. URANS simulations were adopted to investigate the unsteady sweeping jet impingement cooling in a faired cylinder leading edge model at an engine-relevant Biot number (Bi). Heat transfer performance was studied at varying coolant mass flow rates, jet-to-wall spacing (H/D), jet pitch (P/D), and freestream turbulence. The effect of varying aspect ratio (AR) of the sweeping jet geometries was also studied. Numerical simulations were performed to understand the internal fluid dynamics of the impinging sweeping jet, the effect of surface curvature and exit fan angle of the device. Results show that the peak heat transfer for an impinging sweeping jet is lower than the steady jet. The sweeping action of the jet augments local turbulence in the jet shear layer and heats up the core flow as it interacts with the target wall, resulting in a drop in local Nusselt number (Nu). However, the overall cooling uniformity improves due to the sweeping motion of the jet which could be instrumental for gas turbine cooling application where uniform surface temperature is desirable.

Flash Talk Runner-Up

Alexandria Volkening, Post Doctoral Fellow at The Ohio State University
"Forecasting Elections with Mathematical Models of Contagion Spread"
Election forecasting involves polling likely voters, making assumptions about voter turnout, and accounting for features such as state demographics and voting history. While U.S. elections are decided at the state level, errors in forecasting are correlated between states. Here we develop a data-driven framework for forecasting elections from the perspective of dynamical systems. By borrowing ideas from epidemiology and using OSC resources to fit model parameters, we combine a compartmental model of contagion spread with polling data to forecast gubernatorial, senatorial, and presidential elections as accurately as popular pollsters.

Poster Winner

Zhiping Zhong, Post Doctoral Fellow at The Ohio State University
"Viruses Potentially Enhance Hosts Cold- and Salt-Tolerance"
Viruses in polar cryopeg and sea ice were largely ignored. Here we characterized, for the first time, the viral communities in such extreme environments with large metagenomic dataset analyzed using OSC supercomputers. Most (88.3%) viruses were novel. Viral communities varied between environments and across sea ice depths, and significantly correlated with microbial profiles. Viruses likely infected dominant cold- and salt-tolerant microbes and contributed to their hosts’ responses to cold and salt stresses through modulating microbial metabolisms. This study extends the exploration of the virosphere deep into ancient cryopeg and reveals viral impacts on microbial functions in cold and salt environments.

Poster Runner-Up

Harper McMinn-Sauder, Graduate Research Associate at The Ohio State University
"Measuring Honey Bee Utilization of Conservation Reserve Program (CRP) Pollinator Plantings Using DNA Metabarcoding"
Since its introduction in the 1980s to help improve soil quality on agricultural land, the Conservation Reserve Program (CRP) has had a number of positive ecological effects, including reduced habitat fragmentation and increased natural forage for pollinators. One present goal of CRP management is to increase pollinator abundance and diversity by planting native seed mixes that promote foraging. This high-quality habitat provides an excellent opportunity to study honey bee nutrition and identify if floral resources from CRP plantings are being collected by honey bees. This study aims to highlight the primary sources of honey bee forage on CRP land in the northern Midwest. Using citizen science methods, we received pollen trapped samples from beekeepers in Ohio, South Dakota, Indiana, Illinois, and Michigan. Pollen homogenization and metabarcoding methods were used to analyze and quantify pollen collected at different points throughout the season. Results indicate that honey bees located near CRP properties are utilizing diverse genera of pollen floral resources, suggesting that CRP may provide resources comparable to what bees would experience in an undisturbed habitat. In addition, pollen from seven genera in 2016 and eight genera in 2017 was identified from the CRP pollinator seed mix, indicating that honey bees are utilizing this resource. These results have implications regarding colony management as well as land management for foraging honey bees.

SUG Press Release and Photos

Please see our press release and separate OSC Facebook album for additional photos.