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In the present study, the flow inside a real size Diesel fuel injector nozzle was modeled and analyzed under different boundary conditions using ANSYS-Fluent software. A validation was performed by comparing our numerical results with previous experimental data for a rectangular shape nozzle. Schnerr-Sauer cavitation model, which was selected for this study, was also validated. Two-equation k-ε turbulence model was selected since it had good agreement with experimental data. To reduce the computing time, due to symmetry of this nozzle, only one-sixth of this nozzle was modeled. Our present six-hole Diesel injector nozzle was modeled with different needle lifts including 30 μm, 100 μm and 250 μm. Effects of different needle lifts on mass flow rate, discharge coefficient and length of cavitation were evaluated comprehensively. Three different fuels including one Diesel fuel and two bio-Diesel fuels were also included in these numerical simulations. Behavior of these fuels was investigated for different needle lifts and pressure differences. For comparing the results, discharge coefficient, mass flow rate and length of cavitation region were compared under different boundary conditions and for several fuel types. The extreme temperature spike at the center of an imploding cavitation bubble was also analyzed as a function of time and initial bubble size. 

A methodology for non-destructive simultaneous estimation of spatially varying thermal conductivity and heat capacity in 2D solid objects was developed that requires only boundary measurements of temperatures. The spatial distributions were determined by minimizing the normalized sum of the least-squares differences between measured and calculated values of the boundary temperatures. Computing time was significantly reduced for the entire inverse parameter identification process by utilizing a metamodel created by an analytical response surface supported by an affordable number of numerical solutions of the temperature fields obtained by the high fidelity finite element analyses. The minimization was performed using a combination of particle swarm optimization and the BFGS algorithm. The methodology has shown to accurately predict linear and nonlinear spatial distributions of thermal conductivity and heat capacity in arbitrarily shaped multiply-connected 2D objects even in situations with noisy measurement data thus proving that it is robust and accurate. The current drawback of this method is that it requires an a priori knowledge of the general spatial analytic variation of the physical properties. This can be remedied by representing such variations using products of infinite series such as Fourier or Chebyshev and determining correct values of their coefficients. 

Computational analysis of forced conjugate convection cooling of realistic human hearts including main epicardial blood vessels was performed. It was found that including the main epicardaial blood vessels in the forced conjugate cooling analysis accelerated the cooling process and reduced temperature irregularities in the heart tissue, suggesting that usable life of transplantation bound human hearts can be extended from 10.2 to 11.5 hours after extraction from the donor’s body. 

A methodology for non-destructive, accelerated inverse estimation of spatially varying material properties using only boundary measurements is presented. The spatial distribution of diffusion coefficient in 3D solid object is determined by minimizing the sum of the least-squares difference between measured and calculated values. The forward problem is solved using the finite volume and finite element methods, both of which were compared against analytical solution. The inverse problem was solved using an optimization technique to minimize the sum of the least-square errors. The non-destructive estimation was accelerated by the use of surrogate models to solve the forward problem. The presented methodology is applied to measurements containing varying levels of noise. Finally, it is used to detect both the location, size and shape of a subdomain within a solid object and material property of the subdomain material. 

Computational analysis of forced conjugate convection cooling of realistic human hearts including main epicardial blood vessels was performed. It was found that including the main epicardaial blood vessels in the forced conjugate cooling analysis accelerated the cooling process and reduced temperature irregularities in the heart tissue, suggesting that usable life of transplantation bound human hearts can be extended from 10.2 to 11.5 hours after extraction from the donor’s body.