Robin K. Connelly

Assistant Professor, Food Science and Biological Systems Engineering
A19 Babcock Hall
rkconnelly@wisc.edu
(608) 262-8033
FAX (608) 262-6872

Research Interests

My primary research areas within the general area of Food Process Engineering include mixing; dough development, structure and rheology; and computational fluid dynamics (CFD) numerical simulation applied to food processes.

Mixing is an important step in most food processing operations, but the design, use and scale-up of mixers has mainly relied on trial-and-error or rules of thumb that may or may not be appropriate for a given product. A major emphasis of my work is to further the understanding of what is happening during the mixing of complex food materials using both experimentation and numerical simulation, as well as to look at new ways to approach mixing process design and scale-up, in order to improve mixing process efficiency and final product quality.

Dough mixing provides an especially interesting mixing system to study because the mixing is performed not only to homogenously distribute all ingredients, but also to provide energy input in order to develop the gluten. In addition to using CFD to study mixing patterns in dough mixers, my work is delving into how the way energy, as well as water and other ingredients, are input impacts dough development. This has lead to the use of infrared spectroscopy and cereal chemistry approaches to study the changes that occur during dough development due to differences that develop in the dough structure, as well as rheological measurement of the bulk behavior of the dough. In addition, new research is getting underway to study the effects of bran on the development of dough structure in whole grain products.

Computational Fluid Dynamics (CFD) numerical simulation offers a way to put together all the food processing and material property models that have been developed to see if they can actually simulate and predict real phenomena in a realistic setting.. As well as using CFD to study mixing processes, my CFD work has expanded more generally into the study of powder production processes, including two phase simulation of lactose crystallization and spray drying of dairy ingredients. CFD requires accurate physical models, which requires the results of another research interest of mine: the measurement rheological properties and behavior of complex food and biological materials. In addition, the results of CFD require validation in order to be accepted as accurate, which has lead to research using high speed digital imaging to study the in situ behavior of actual processes.

See “The Physics of Making Food” in the CALS Science Report 2006-2007.

Robin Connelly page at Biological Systems Engineering.

Education

• B.S. Agricultural Engineering, Michigan State University, 1987
• M.S. Chemical & Biochemical Engineering, Rutgers The State University of New Jersey, 1992
• Ph.D. Food Science, Rutgers The State University of New Jersey, 2004

Scientific And Professional Organizations

• Rheology Research Center, University of Wisconsin-Madison
• Institute of Food Technologists
• The Society of Rheology
• American Institute of Chemical Engineers
• Member of North American Mixing Forum (NAMF)
• American Association of Cereal Chemists International
• American Society of Agricultural and Biological Engineers

Selected Publications

Bock, J. And Connelly, R.K. 2008. Innovative Uses of Near-Infrared Spectroscopy in Food Processing. J. Food Sci., Accepted for publication.

Connelly, R.K. and Valenti-Jordan, J.B. 2008. Mixing Analysis of a Newtonian Fluid in a 3D Planetary Pin Mixer. Proceedings of the International Symposium on Mixing in Industrial Processes 6, Niagara Falls, Ontario, Canada, Aug. 17-21.

Hartel, R.W., Howell, Jr., T.A., Connelly, R.K., and Hyslop, D.B. 2008. Math Concepts for Food Engineers, 2nd edition, Taylor and Francis Group, CRC Press, LLC, Boca Raton, FL.

Connelly, R.K. and Kokini, J.L. 2007. Analysis of Mixing Processes Using CFD. Chapter 23, pgs. 555-588 in Computational Fluid Dynamics in Food Processing, Da-Wen Sun (ed.), Taylor and Francis Group, LLC, Boca Raton, FL.

Connelly, R.K. and Kokini, J.L. 2007. Examination of the mixing ability of single and twin screw mixers using 2D Finite Element Method simulation with particle tracking. J. Food Engr. 79(3): 956-969.

Connelly, R.K. and Kokini, J.L. 2006. Mixing Simulation of a Viscous Newtonian Liquid in a Twin Sigma Blade Mixer. AIChE J. 52(10): cover, 3383-3393.

Connelly, R.K. and Kokini, J.L. 2006. 3D numerical simulation of the flow of viscous Newtonian and shear thinning fluids in a twin sigma blade mixer. Adv. Poly. Tech. 25(3):182-194.

Connelly, R.K. and Kokini, J.L. 2004. Analysis of mixing in a model mixer using 2-D numerical simulation of differential viscoelastic fluids with particle tracking. J. Non-Newt. Fluid Mech. 123:1-17.

Connelly, R.K. and Kokini, J.L. 2003. 2-D Numerical Simulation of Differential Viscoelastic Fluids in a Single-Screw Continuous Mixer: Application of Viscoelastic FEM Methods. Adv. Poly. Tech. 22(1):22-41.