Chris J. Kobus, Ph.D.

Associate Professor of Engineering

Department of Mechanical Engineering

Oakland University

Rochester, Michigan 48309

Email: cjkobus@oakland.edu

Office: 148 Dodge Hall of Engineering

Phone: (248) 370-2489

Fax: (248) 370-4416

Oakland University

Rochester, MI 48309

Welcome to my homepage. I am currently an Associate Professor of Engineering for the Mechanical Engineering Department at Oakland University. As you can probably surmise from my educational background above, I have had a long and storied relationship with OU, and in fact with southeastern Michigan.

I was always involved with the OU community even as an undergraduate student, holding positions in several engineering societies such as ASME, tau beta pi, NSPE, AIAA, as well as being on the OU Student Congress. In addition, I supported myself by being a mathematics tutor and supplemental instructor at the Academic Skills Center (algebra to precalc, to calculus to diff eq.). I was also an Orientation Group Leader (OGL) and a night manager at the Oakland Center.

I remain at OU because I believe it is a unique institution amonsgt all others. Insofar as engineering goes, the School has a unique balance between teaching and research excellence; a balance that is rare to find elsewhere. In addition, the OU community is diverse and students are exposed to a multitude of experiences. When I was a doctoral student, I was given an opportunity to teach an undergraduate engineering course. I found that I had a passion for teaching, one that I am fortunate to be able to fulfill throughout the academic year. In addition, I have the freedom to do research on the side with undergraduate and graduate students, which is very gratifying. Check out some of my former projects here.

Aside from my professional life, I am married and have five children.

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Areas of Interest:

1. Alternative, renewable and Sustainable Energy Systems
2. Combined Forced and Natural Convective Heat Transfer; Boundary Layer Theory and Experimental Techniques
3. Transient and Unstable Behavior in Two-Phase Evaporating and Condensing Flow; Single and Multitube Systems
4. Analytical and Experimental Techniques Associated with Steady-State and Time Varying Fluid and Thermal Systems, Components, Processes and Phenomena
5. Phenomenological paradigm development for engineering education; teaching and learning techniques and technique implementation. Use of hands-on laboratory and design experiences for retention of basic and advanced engineering skills. K-12 readiness for secondary-level engineering education

Alternative Energy Systems.  This area includes solar, wind and biomass energy conversion (which in turn includes ethanol and biodiesel).  Current Research in Progress: wind turbine sighting at Oakland University .  Conversion of feedstock to biodiesel and ethanol including waste energy utilization.  Turning waste streams into additional revenue streams in biomass processing and utilization.  Waste heat utilization in conventional and unconventional energy conversion systems, components and processes in the process, chemical, power and transportation industries.

Combined Forced and Natural Convective Heat Transfer; Boundary Layer Theory and Experimental Techniques. The mode of convective heat transfer that is neither dominated by pure forced nor pure natural convection, but is rather a combination of the two, is appropriately referred to as combined, or mixed, forced and natural convection. In such a situation, the relative direction of the buoyancy force and the externally forced flow is important. In the case where the externally forced flow is in the same direction as that of the buoyancy force, the mode of thermal energy transport is termed assisting (or aiding) combined convection. Similarly, in the case where the externally forced flow is in a direction directly opposite that of the buoyancy force, the mode of thermal energy transport is termed opposing combined convection. Relatively little research exists for combined convection as compared with pure forced or pure natural convection. Current Work in Progress: Utilization of commercially available disk-type thermistor heat transfer models for indirectly measuring convective heat transfer coefficients for natural and combined convection, various disk orientations, empirical correlations. Development of a modified Reynold’s number that incorporates a characteristic velocity for natural convection, which has the advantage of being able to plot forced, natural and combined convection data on a single graph. Combined forced and natural convection boundary layer theory development.

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Transient and Unstable Behavior in Two-Phase Evaporating and Condensing Flow; Single and Multitube Systems. This research is important mainly because large flow oscillations of the condensate in single-tube and multitube condensing flow systems could substantially affect the performance, control and safety of these and other associated systems. Central in the development of the governing equations is the System Mean Void Fraction (SMVF) Model, which is a one-dimensional, two-fluid, distributed parameter integral model describing the primary physical mechanisms within the two-phase region, and which incorporates the concept of a non-fluctuating system mean void fraction. This concept makes the problem more open to closed-form analytical solution, and will therefore yield valuable insight into the influence of the relevant physical parameters on the transient characteristics of the condensing flow systems. Current Research in Progress: Prediction of Transients and Instabilities in Multitube Two-Phase Condensing Flow Systems; Predicting the Influence of Heat Flux on Horizontal Single-Tube Condensing Flow Systems, Predicting the Influence of Gravity in Vertical Condensing Flow Systems, Upflow and Downflow; Predicting the Effect of Subcooled Liquid Inertia on Transient- and Frequency Response Characteristics of Single and Multitube Condensing Flow Systems. Scaling two-phase flow phenomena to mini- and micro-channels.

Analytical and Experimental Techniques Associated with Time Varying and Steady State Fluid and Thermal Systems, Components, Processes and Measurements. This is a very broad area of research that involves the formulation and development of simplified theoretical models that include the dominant physical mechanisms. The simplified models are usually more agreeable to closed-form analytical solution, and therefore yield important insight into the influence of the relevant physical parameters on the transient characteristics of the phenomena. Current Research in Progress: Predicting Steady-State conduction error and transient lag error in temperature measurements; predicting the bulk fuel temperature in fuel tanks and fuel delivery systems; predicting evaporative emissions from fuel tanks based on thermal loading parameters.

Phenomenological paradigm development for engineering education; teaching and learning techniques and technique implementation. Use of hands-on laboratory and design experiences for retention of basic and advanced engineering skills. K-12 readiness for secondary-level engineering education. Current Research in Progress: Implementation of Kumon training in K-12 education in the Pontiac school district for improving retention of math skills towards secondary education.

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PUBLICATIONS

Refereed Journal Publications

1. Kobus, C. J., “On Condensate Inertia Enhanced Transient Thermal Amplification Characteristics, Flow Reversals and Surges in Horizontal Two-Phase Condensing Flow Systems due to Perturbations in Inlet Vapor Flowarate,” accepted in the International Journal of Multiphase Flow.
2. Kobus, C. J., 2006, “An Experimental Investigation into Natural Convection Heat Transfer from Stationary, Uniformly Heated (Isoflux) Thin Circular Disks,”Experimental Thermal and Fluid Science, Vol. 31, No. 3, pp. 191-195.
3. Kobus, C. J., 2006, “True Fluid Temperature Reconstruction Compensating for Conduction Error in the Temperature Measurement of Steady Fluid Flows,” Review of Scientific Instruments, Vol. 77, No. 3.
4. Kobus, C. J. and Tison, N., 2006, "A Distributed Parameter Integral Model for Predicting the Thermal Performance Characteristics of Radiation Heat Shield Systems,” Heat and Mass Transfer, Vol. 42, No. 12, pp. 1143-1154.
5. Kobus, C.J. and Oshio, T., 2006, "Thermal Performance Characteristics of a Staggered Vertical Pin Fin Array Heat Sink with Assisting Mixed Convection in External and In-Duct Flow Configurations," Experimental Heat Transfer, Vol. 19, No. 2, pp. 129 - 148.
6. Kobus, C.J. and Cavanaugh, R.B., 2006, "A Fundamental Investigation into Pin Fins of Least Material Under Pure Forced and Pure Natural Convection with Variable Convective Heat Transfer Coefficient," ASME Journal of Heat Transfer, Vol. 128, No. 8, pp. 845 - 846.
7. Kobus, C. J. and Shumway, G., 2006, "An Experimental Investigation into Impinging Forced Convection Heat Transfer from Stationary Isothermal Circular Disks", International Journal of Heat and Mass Transfer. Vol. 48, Nos. 1-2, pp. 411 – 414.
8. Kobus, C. J., 2005, “Utilizing Disk Thermistor to Indirectly Measure Convective Heat Transfer Coefficient for Forced, Natural and Combined (Mixed) Convection,” Experimental Thermal and Fluid Science, Vol. 29, No. 6, pp. 659 – 669.
9. Kobus, C. J., 2005, "An Investigation into the Effect of Subcooled Liquid Inertia on Flow Change Induced Transient Flow Surges in Horizontal Condensing Flow Systems", ASME Journal of Heat Transfer, Vol. 127, No. 11, pp. 1280 - 1284.
10. Kobus, C.J. and Oshio, T., 2005, "An Experimental Investigation into Optimal Spacing in a Pin Fin Array with an Impinging Jet and Combined Forced and Natural Convection," International Journal of Heat and Mass Transfer., Vol. 48, No. 6, pp. 1053 - 1063.
11. Kobus, C.J. and Oshio, T., 2005, "Predicting the Thermal Performance Characteristics of Staggered Vertical Pin-Fin Array Heat Sinks under Combined Mode Radiation and Mixed Convection with Impinging Flow," International Journal of Heat and Mass Transfer, Vol. 48, No. 13, pp. 2684 - 2696.
12. Kobus, C. J. and Wedekind, G. L., 2002, “An Investigation into Natural Convection Heat Transfer from Isothermal Thin Circular Disks at Arbitrary Angles of Inclination," International Journal of Heat and Mass Transfer, Vol. 45, No. 5, pp. 1159 - 1163.
13. Kobus, C. J. and Wedekind, G. L., 2001, “An Experimental Investigation into Natural Convection Heat Transfer from Horizontal Isothermal Circular Disks," International Journal of Heat and Mass Transfer, Vol. 44, No. 17, pp. 3381 - 3384.
14. Kobus, C. J., Wedekind, G. L. and Bhatt, B. L., 2001, “Predicting the Onset of a Low-Frequency Self-Sustained Oscillatory Flow Instability in Multitube Two-Phase Condensing Flow Systems”, ASME Journal of Heat Transfer, Vol. 123, No. 2, pp. 319 - 330.
15. Kobus, C. J., Wedekind, G. L. and Bhatt, B. L., 2000, “Predicting the Influence of Compressibility and Thermal and Flow Distribution Asymmetry on the Frequency-Response Characteristics of Multitube Two-Phase Condensing Flow Systems”, ASME Journal of Heat Transfer, Vol. 122, No. 1, pp. 196 - 200.
16. Oakley, B., Wright, F., Barber, G., Latcha, M., Kobus, C. J. and Grim, P., 1999, “A Self-Contained, Portable Variable-Pressure Hydrostatic Cell for Use in Low Gauge Pressure Electromagnetic, Ultrasonic, and Photoacoustic Studies”, Review of Scientific Instruments, Vol. 70, No. 1, pp. 95 - 97.
17. Kobus, C. J., Wedekind, G. L. and Bhatt, B. L., 1998, “Application of an Equivalent Single-Tube Model for Predicting Frequency-Response Characteristics of Multitube Two-Phase Condensing Flow Systems with Thermal and Flow Distribution Asymmetry”, ASME Journal of Heat Transfer, Vol. 120, No. 2, pp. 528 - 530.
18. Wedekind, G. L., Kobus, C. J. and Bhatt, B. L., 1997, “Modeling the Characteristics of Thermally Governed Transient Flow Surges in Multitube Two-Phase Condensing Flow Systems with Compressibility and Thermal and Flow Distribution Asymmetry”, ASME Journal of Heat Transfer, Vol. 119, No. 3, pp. 534 - 543.
19. Kobus, C. J. and Wedekind, G. L., 1996, “Modeling the Local and Average Heat Transfer Coefficient for an Isothermal Vertical Flat Plate with Assisting and Opposing Combined Forced and Natural Convection”, International Journal of Heat and Mass Transfer, Vol. 39, No. 13, pp. 2723 - 2733.
20. Wedekind, G. L. and Kobus, C. J., 1996, “Predicting the Average Heat Transfer Coefficient for an Isothermal Vertical Circular Disk with Assisting and Opposing Combined Forced and Natural Convection”, International Journal of Heat and Mass Transfer, Vol. 39, No. 13, pp. 2843 - 2845.
21. Kobus, C. J. and Wedekind, G. L., 1995, “An Experimental Investigation into Forced, Natural and Combined Forced and Natural Convective Heat Transfer from Stationary Isothermal Circular Disks”, International Journal of Heat and Mass Transfer, Vol. 38, No. 18, pp. 3329 - 3339.
22. Wedekind, G. L. and Kobus, C. J., 1994, “Modeling Thermally Governed Transient Flows in Multitube Evaporating Flow Systems with Thermal and Flow Distribution Asymmetry” ASME Journal of Heat Transfer, Vol. 116, pp. 503 - 505.

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Papers Under Review or In Progress

1. Kobus, C. J., Wu, D., Raikar, V. and Guessous, L., 2006 “Modeling the Fundamental Prandtl Number Dependence for Isothermal and Uniformly Heated (Isoflux) Three-Dimensional Bodies,” under preparation to the International Journal of Heat and Mass Transfer.
2. Kobus, C. J. and Wu, D., “An Integral Model for Natural Convection Heat Transfer from a Right Circular Cone,” under preparation to the International Journal of Heat and Mass Transfer (2007).
3. Kobus, C. J. and Tison, N., “Predicting the Thermal Performance Characteristics of Radiation Heat Shield Systems,” under preparation in the Journal of Automotive Engineering (2007).
4. Kobus, C. J., “Modeling Transient Lag Error in the Measurement of Time-Varying Fluid Temperature,” under preparation in Review of Scientific Instruments (2007).
5. Kobus, C. J., “Temperature Reconstruction from Thermocouples and Thermowells Influenced by Coupled Transient Lag and Conduction Error,” under preparation in Review of Scientific Instruments (2007).
6. Kobus, C. J., and Wu, D., “Utilizing Rod-Shaped Disk Thermistors to Indirectly Measure Convective Heat Transfer Coefficients for Natural Convection in Various Prandtl Number Fluids,” under preparation to the International Journal of Heat and Mass Transfer (2007).
7. Kobus, C. J., “Utilizing the Integral Technique to Explicitly Find the Similarity Variable Converting Partial to Ordinary Differential Equations,” under preparation to the International Journal of Heat and Mass Transfer (2007).

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Other Publications

1. Kobus, C. J., “Application of the System Mean Void Fraction Model in Formulating an Equivalent Single-Tube Model for Predicting Various Transient and Unstable Flow Phenomena Associated with Horizontal Multitube Two-Phase Condensing Flow Systems with and without the Effects of Compressibility, Inertia, and Thermal and Flow Distribution Asymmetry”, Ph.D. Thesis, Oakland University, Rochester, Michigan, April, 1998.

Conference Proceedings

1. Guessous, L., Kobus, C. J., Barber, G., Sangeorzan, B.P., Zou, Q., Alkidas, A. Latcha, M. and Wang, X., “Generating Enthusiasm For Research Through Automotive Projects And Industrial Mentors: Lessons Learned From The First Year Of An Reu Program,” Proceedings of the 2007 ASEE Annual Conference and Exposition, Honolulu, HI, June 24-27 (2007).
2. Kobus, C. J., Y. H. Wu, "Utilizing the Integral Technique to Model Natural Convection from a Right Circular Cone," Proceedings of the 2007 ASME/JSME Joint Thermal Conference, Vancouver, CAN, July 8-12 (2007).
3. Kobus, C. J., Y. H. Wu and L. Guessous, “Utilizing Disk Shaped Thermistors To Experimentally Determine The Prandtl Number Dependence Ranging From Vapors To Liquids,” Proceedings of the 2006 ASME International Mechanical Engineering Congress and R&D Expo (IMECE), Chicago, IL, November 5-11 (2006).
4. Kobus, C. J., Y. H. Wu and L. Guessous, “Indirectly Measuring Convective Heat Transfer Coefficients From Self-Heated Rod-Shaped Thermistor,” Proceedings of the 2006 ASME Summer Heat Transfer Conference, San Francisco, CA, June 5-11 (2006).
5. Kobus, C.J., "A Material Utilization Factor for Quantifying the Performance of Optimal Shape Extended Surfaces of Minimum Volume," Proceeding of the 2005 ASME International Mechanical Engineering Congress and R&D Expo (IMECE), November 5-11, Orlando, Florida (2005).
6. Kobus, C.J., "An Investigation into Horizontal Pin Fins of Least Material under the Influence of Natural Convection," Proceeding of the 2005 ASME Heat Transfer Summer Conference, July 17-22, San Francisco, California (2005).
7. Cavanaugh, R.B., Kobus, C.J., "A Fundamental Investigation into Pin Fins of Least Material; New Insight into an Old Problem," Proceedings of the 2004 ASME International Mechanical Engineering Congress and R&D Expo (IMECE), November 13-19, Anaheim, California (2004).
8. Kobus, C. J., Raikar, V. and Guessous, L., "Utilizing the Integral Technique for Obtaining a New Dimensionless Group for Predicting Prandtl Number Dependence for Natural Convection Heat Transfer From an Isothermal Vertical Flat Plate" Proceeding of the 2004 ASME Heat Transfer/Fluids Engineering Division (HT/FED) Summer Conference, July 11-15, Charlotte, North Carolina (2004).
9. Kobus, C. J., Guessous, L. and Raikar, V. , "Modeling Natural Convection Heat Transfer from a Uniformly Heated Vertical Plate" Proceesdings of the ASME International Mechanical Engineering Congress and R&D Expo (IMECE), November 16-21, Washington D.C. (2003).
10. Kobus, C. J., “An Investigation into the Effect of Subcooled Liquid Inertia on Flowrate Induced Transient Flow Surges in Horizontal Condensing Flow Systems,” Proceedings of the 2003 ASME Summer Heat Transfer Coinference, July 20-23, Las Vegas, Nevada (2003).
11. Kobus, C. J., “An Investigation into the Effect of Subcooled Liquid Inertia on Flowrate Induced Frequency-Response Characteristics of Horizontal Condensing Flow Systems,” Proceedings of the 6th ASME/JSME Thermal Engineering Joint Conference, March 16 - 20, Hawaii (2003).
12. Kobus, C. J., “An Investigation into Heat Flux Induced Transient Flow Surges in Horizontal Condensing Flow Systems,” Proceedings of the 6th ASME/JSME Thermal Engineering Joint Conference, March 16 - 20, Big Island of Hawaii, Hawaii (2003).
13. Kobus, C. J., “A Unique Leak Detection Precursor Capstone Design Project for a Hands-On Senior-Level Design Experience,” Proceedings of the 2003 American Society of Engineering Education (ASEE) Annual Conference & Exposition, June 22 - 25, Nashville, Tennessee (2003).
14. Oakley, B., Lawrence, D., Kobus, C.J., Barber, G. and Burt, W., “Using the Kumon Method to Revitalize Mathematics in an Inner-Urban School District,” Proceedings of the 2003 American Society of Engineering Education (ASEE) Annual Conference & Exposition, June 22 - 25, Nashville, Tennessee (2003).
15. Wedekind, G. L. and Kobus, C. J., “A Unique Liquid-Vapor Thermodynamic Property Measurement Apparatus For A Hands-On Undergraduate Laboratory Experience,” Proceedings of the 2002 American Society of Engineering Education (ASEE) Annual Conference and Exhibition, June 16 - 19, Montreal, Quebec, CAN (2002).
16. Wedekind, G. L. and Kobus, C. J., “Convection Heat Transfer Measurement for Student Labs; Part I : Forced Convection,” Proceedings of the 2002 American Society of Engineering Education (ASEE) North Central Section Regional Conference, April 5 - 6, Rochester, MI (2002).
17. Kobus, C. J. and Wedekind, G. L., “Convection Heat Transfer Measurement for Student Labs; Part II : Natural Convection,” Proceedings of the 2002 American Society of Engineering Education (ASEE) North Central Section Regional Conference, April 5 - 6, Rochester, MI (2002).
18. Wedekind, G. L. and Kobus, C. J., “Design in the Curriculum: Design of a Concentric-Tube Thermal Energy Recuperator for Optimal Cost Savings,” Proceedings of the 2001 ASEE North Central Section Regional Conference, April 6 - 7, Cleveland, OH. This paper received the Best Overall Paper Award at the 2001 ASEE North Central Section Annual Conference (2001).
19. Wedekind, G. L. and Kobus, C. J., “Optimal Design of a Thermal Recuperator,” Proceedings of the 2001 ASEE Annual Conference and Exhibition, June 24 - 27, Albuquerque, NM (2001).

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AWARDS AND HONORS

Bhushan L. Bhatt, Ph.D.; Professor and Associate Dean

Laila Guessous, Ph.D.; Assistant Professor

Brian P. Sangeorzan, Ph.D.; Associate Professor