NSF Award
2333138
This Major Research Instrumentation (MRI) award supports the acquisition of a spray particle and spray droplet size analyzer for precision manufacturing technology and semiconductor technology. Grinding operations in manufacturing produce substantial heat which can cause damage to the component being made. Coolant must be delivered to the grinding surface, but this coolant can be easily mixed with air causing is to be less effective. The spray particle and spray droplet size analyzer will provide measurements of the break-up of a coolant jet during grinding and will enable improved coolant nozzle design and coolant delivery modeling. This instrument will enable research on variety of materials, including those that are hard-to-grind and hard to dissipate heat, and coolant properties. Improvements in cooling will reduce heat pollution in the environment, which is substantial in the grinding industry. The instrument will also enable evaluation and mitigation of the spread of oil-based coolant and formation of oil mist that represents a fire hazard and safety hazard when inhaled. The instrument will enhance research and training in the Center for Precision Manufacturing at the University of Akron and benefit the Northeastern Ohio region which is home to over 30% of the State of Ohio’s manufacturing workers. The students who will benefit from the instrument, including those from communities under-represented in engineering, will gain hands-on training and knowledge spanning fundamentals of fluid dynamics and heat transfer to the needs of the manufacturing and semiconductor industries.<br/><br/>If the heat produced during grinding is not managed properly it can lead to thermal damage such as tensile residual stresses, discoloration, softening, re-hardening, and cracks. Coherent (laminar) jets provide coolant fluid delivery for maximized lubrication at the contact zone critical to defect-free grinding at high material remove rates. Turbulent jet spread does not allow the coolant jet to effectively breach the high-speed air boundary layer - created by entrainment of air along the surface of rapidly rotating grinding wheel - and gain access to the hot wheel-to-workpiece interface. It is unknown to what degree sprayed coolant is delivered to the grinding zone. The spray particle and spray droplet size analyzer will enable improved understanding of the laminar to turbulent transition of a fluid jet under various working conditions. Numerical modeling of the disintegration and transition to turbulence of coherent coolant jets represents challenges that will be overcome using the instrument to verify numerical model of jet break-up. The ability to accurately model coolant jet coherence is a potential game changer in the field of metalworking. To validate the numerical model, the performance of manufactured nozzles will be studied experimentally using the instrument. Also, the presence of particles in the coolant causes contamination of the nozzle that affects the jet disintegration. The evaluation of jet coherence together with quantification of particles in the jet will assist in prediction of need for replacement of the nozzle. Selection of cooling jet parameters to ensure that the jet is coherent will be achieved by studying jet break-up using the acquired instrument.<br/><br/>This project is jointly funded by the Major Instrumentation Research Program (MRI) and the Advanced Manufacturing Program (AM) in the division of Civil, Mechanical and Manufacturing Innovation (CMMI).<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
