Schmidt

Research Interests:

My areas of research include sprays, cavitation, and other multiphase flows. Sprays are especially important for combustion. For diesel engines and gas turbines, the spray quality has a tremendous impact on the emissions. Just consider how many diesels and airplanes are carrying people and goods around the globe. The ability to reduce their emissions through better understanding of sprays is very important.

Diesel fuel injection is especially interesting because it combines cavitation with sprays. The fuel injector nozzles are usually cavitating. This cavitation process enhances the liquid atomization. The connection between the nozzles and the spray is very complicated.

Once the liquid comes out of the nozzle, it breaks up into droplets. This is called "primary atomization." The exact details of the process in high-speed flows are unknown. I, and many others, have worked hard to make reasonable estimates of what happens. Once formed, the droplets can break up further, or they can collide with other drops. The drops also can evaporate and exchange heat with the surrounding gas. Turbulent eddies in the gas disperse drops, too.

All of these processes affect the mixing of fuel and air for combustion. The quality of this mixing will help determine how much pollution is formed in the engine. By developing modeling tools, engineers can predict what designs will work best. The models also produce physical insights, too.

Selected Publications:

DAVID P Matthew J. Frain, David P. Schmidt, and Woodrow Fiveland, “An Experimental Investigation of the Influence of gas and Solid Particle Interaction on the Heat Transfer Effectiveness of a Falling-Bed Heat Exchanger,” Int. J. of Heat and Mass Transfer, in press, 2005.

Sasanka Are, Shuhai Hou, David P. Schmidt, “Second Order Spatial Accuracy in Lagrangian-Eulerian Spray Calculations,” Numerical Heat Transfer, in press 2005.

Meizhong Dai and David P. Schmidt, “Adaptive Tetrahedral Meshing in Free-Surface Flow,” J. Comp. Phys., in press, 2005.

Meizhong Dai and David P. Schmidt, “Numerical Simulation of Head-On Droplet Collision: Effect of Viscosity on Maximum Deformation,” Phys. Fluids, 17(4), 2005.

David P. Schmidt and C.J. Rutland, “Reducing Grid Dependency in Droplet Collision Calculations,” ASME Journal for Gas Turbines and Power, April, 2004.

David P. Schmidt, Lou Chiappetta, Graham Goldin, and Ravi Madhabushi, “Transient Multidimensional Modeling of Airblast Atomizers,” Atomization and Sprays, v. 13, n. 4 , 2003.

David P. Schmidt, “Improving the Numerical Accuracy of Spray Simulations”, SAE Transactions, Journal of Engines, pp. 1826-1835, 2002.

Meizhong Dai, Haoshu Wang, J. Blair Perot, and David P. Schmidt, “Direct Interface Tracking of Droplet Deformation,” Atomization and Sprays, v. 12 n. 5-6, 2002.

"Accuracy and Conservation Properties of a Three Dimensional Unstructured Staggered Mesh Scheme for Fluid Dynamics," Xing Zhang, David Schmidt, and Blair Perot, Journal of Computational Physics, in press, 2001.

"The Internal Flow of Fuel Injector Nozzles: A Review," D. Schmidt and M. L. Corradini, International Journal of Engine Research, v.2, n.1, 2001.

"Multi-Dimensional Modeling of Multiphase Flow Physics: High-Speed Nozzle and Jet Flows-A Case Study," J. Murphy, D. Schmidt, S. P. Wang, and Michael L. Corradini, Nuclear Engineering and Design, v. 204, pp. 177-190, 2001.

"A New Droplet Collision Algorithm," David P. Schmidt and C. J. Rutland, Journal of Computational Physics, v. 164, pp. 62-80, 2000.

David P. Schmidt, Idriss Nouar, P.K. Senecal, Jeff Hoffmann, Jay Martin, C.J. Rutland, R.D. Reitz, "Pressure-Swirl Atomization in the Near Field," 1999 SAE Congress, SAE 1999-01-0496.

David P. Schmidt, Christopher J. Rutland, M. L. Corradini, P. Roosen, and O. Genge," Cavitation in Two-Dimensional Asymmetric Nozzles," 1999 SAE Congress, SAE 1999-01-0518.

P.K. Senecal, D.P. Schmidt, et al., "Modeling high-speed viscous liquid sheet atomization," Int'l. J. of Multiphase Flow, v. 25, 1999.

David P. Schmidt, Christopher J. Rutland, and M. L. Corradini, "A Fully Compressible Model of Small, High Speed, Cavitating Nozzle Flows," Atomization and Sprays v.9, pp. 255-276, 1999.

David P. Schmidt and M. L. Corradini, "Analytical Prediction of the Exit Flow of Cavitating Orifices," Atomization and Sprays, v. 7, n. 6, pp. 603-616, 1997.

David P. Schmidt, Christopher J. Rutland, and M. L. Corradini, "A Numerical Study of Cavitating Flow Through Various Nozzle Shapes," Transactions of the SAE, 1997.

Contact Information:

Office:

210B Marston Hall

Mail:

David Schmidt

MIE Department

ELAB 219

University of Massachusetts

Amherst, MA 01003-2210

Phone:

(413) 545- 1393

Fax: