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Numerical Simulations Of Cavitation In The Oil Pump And Thin-Fluid-Bearing For Automotive Applications, Jiaqi Xu
Electronic Theses and Dissertations
The cavitation in hydraulic pumps and fluid bearings could cause system instability, wearing, and failure. Modern commercial computational fluid dynamics (CFD) solvers such as Simerics Inc and GT-Suite have the capabilities of predicting cavitation. However, the fidelity and accuracy of those models require further evaluation. The aim of the thesis is to develop a methodology to improve the analysis of oil flow and cavitation in the oil circuit. The research project is conducted jointly by the University of Windsor and Politecnico di Torino. 3D CFD models of the vane pump and journal bearing are simulated using Simerics Inc to evaluate …
Hydrodynamic Cavitation As In-Line Process To Control Common Dairy Sporeformers, Pratibha Chaudhary
Hydrodynamic Cavitation As In-Line Process To Control Common Dairy Sporeformers, Pratibha Chaudhary
Electronic Theses and Dissertations
Sporeforming bacteria and their endospores have the ability to survive thermal treatments and proliferate in the milk and dairy products to cause spoilages. We applied the effect of hydrodynamic cavitation in controlling these bacteria and their spores at pilot scale level. Our aim was to investigate a technology that would improve the microbial quality of milk and dairy products, and is capable of being scaled up to be adapted at industrial level. Cavitation damages the cell walls of the bacteria and their endospores (releasing dipicolinic acid, responsible for endospore resistance to extreme conditions), thereby making them susceptible to thermal treatments …
Objective Predictor Metric Of Annoyance For Hydraulic Engine Mount Cavitation, John Powell
Objective Predictor Metric Of Annoyance For Hydraulic Engine Mount Cavitation, John Powell
Electronic Theses and Dissertations
Vehicle acoustics has been found to have a direct impact on customer experience. Unexpected noises play a role in this experience. Hydraulic engine mount cavitation, the noise heard from the collapse of vapor bubbles in the mount, is considered one of those unexpected noises. During the design phase of a vehicle when an unexpected noise is found there is a need for a method to quantify how much of the noise is too much. Subjective evaluations alone are not enough due to variability from engineer to engineer. An objective way needed to be developed in order to evaluate the cavitation …
Cavitation In Vial Drop Subjected To Mechanical Shock, Houman Babazadehrokni
Cavitation In Vial Drop Subjected To Mechanical Shock, Houman Babazadehrokni
Electronic Theses and Dissertations
Cavitation is a phenomenon that occurs when the local pressure falls down below the critical pressure. Previous work from the Randolph lab demonstrated that protein aggregates can form when a vial of therapeutic solution is dropped onto a hard surface. The process by which this occurs is most likely shock induced cavitation. During this process, hot spots can be created with temperatures and pressures reaching thousands of Kelvin and hundreds of atmospheres, respectively, leading to degradation of protein therapeutics. This work will extend previous efforts by exploring differences generated by change in vial materials, solutions, drop methods and fill volumes. …
Cavitation In Pharmaceutical Manufacturing And Shipping, Donn Sederstrom
Cavitation In Pharmaceutical Manufacturing And Shipping, Donn Sederstrom
Electronic Theses and Dissertations
Therapeutic proteins are used to successfully treat hemophilia, Crohn's Disease, diabetes, and cancer. Recent product recalls have occurred because of sub-visible particle formation resulting from the inherent instability of proteins. It has been suggested that particle formation is associated with late stage processing steps of filling, shipping, and delivery. Previous work at the University of Denver demonstrated that fluid cavitation can generate a large number of sub-visible protein particles in ultra clean formulations, but that mitigation can be achieved with fluid property manipulation. The goal of this research was to (1) assess the risk of cavitation under common pharmaceutical manufacturing …
A Hybrid Constitutive Model For Creep, Fatigue, And Creep-Fatigue Damage, Calvin Stewart
A Hybrid Constitutive Model For Creep, Fatigue, And Creep-Fatigue Damage, Calvin Stewart
Electronic Theses and Dissertations
In the combustion zone of industrial- and aero- gas turbines, thermomechanical fatigue (TMF) is the dominant damage mechanism. Thermomechanical fatigue is a coupling of independent creep, fatigue, and oxidation damage mechanisms that interact and accelerate microstructural degradation. A mixture of intergranular cracking due to creep, transgranular cracking due to fatigue, and surface embrittlement due to oxidation is often observed in gas turbine components removed from service. The current maintenance scheme for gas turbines is to remove components from service when any criteria (elongation, stress-rupture, crack length, etc.) exceed the designed maximum allowable. Experimental, theoretical, and numerical analyses are performed to …
Protein Aggregation Through Acoustic Cavitation, John A. Giarratano
Protein Aggregation Through Acoustic Cavitation, John A. Giarratano
Electronic Theses and Dissertations
Therapeutic proteins represent an essential piece of a health management plan for diseases such as diabetes, cancer, hemophilia, Crohn's Disease, and myocardial infarction. These proteins, however, must be maintained in their correct, biologically active conformation throughout processing, transportation, and delivery. This requirement poses serious engineering challenges because of a protein's susceptibility to thermodynamic instabilities resulting from the weak bonds driving the tertiary structure of the molecule. A particularly problematic type of protein degradation is aggregation. Administration of aggregated proteins, a particularly problematic degradation form, can have dire consequences, including blocking a patient's responsiveness to therapy, inducing immunogenicity, and even anaphylactic …
The Effect Of Static Pressure On The Inertial Cavitation Threshold And Collapse Strength, Kenneth Bryan Bader
The Effect Of Static Pressure On The Inertial Cavitation Threshold And Collapse Strength, Kenneth Bryan Bader
Electronic Theses and Dissertations
The amplitude of the acoustic pressure required to nucleate a gas and/or vapor bubble in a fluid, and to have that bubble undergo an inertial collapse, is termed the inertial cavitation threshold. The hydrostatic dependence of the inertial cavitation threshold was measured up to 30 MPa in ultrapure water using a high quality factor spherical resonator. The threshold increased linearly with the hydrostatic pressure and was found to be temperature dependent. The strength of the bubble collapse at the threshold was measured in terms of shock waves and light emissions. The shock amplitudes increased linearly with the hydrostatic pressure, while …