Research

Summary

Professor Yuen’s research interest is in the areas of radiation heat transfer, fire safety, high heat flux electronic cooling, and two-phase flow in nuclear reactor safety. His research has been funded by NSF, NRC, DOE, and NASA. He has published over one hundred and twenty refereed technical papers.

The most significant papers/websites he has published over the years are listed below:

1. Radiation Heat Transfer

Professor Yuen has devoted much of his research career to the development of numerical method in radiation heat transfer for non-gray, combustion media in multi-dimensional enclosures. He is the originator of the concept of Generalized Zonal Method (GZM) and Multiple Absorption Coefficient Zonal Method (MACZM). His goal is to develop an efficient and accurate numerical method so that the radiation heat transfer effect in combustion scenarios can be assessed.

Professor Yuen also devoted a great deal of his research to the development of numerical method for highly scattering media such as fibrous insulation. Due to scattering, the radiant transport through fibrous insulation is inherently multi-dimensional. The Generalized Zonal Method (GZM) is demonstrated to be a suitable solution technique for this class of problems.

Some important websites and publications are listed below;

Websites:

RADNNET(http://radnnet.makinoharashoko.me) Calculation of Emissivity/Absorptivity of a CO2/H2O/N2/soot Mixture with RADNNET)

RADNNET computes the total emissivity and absorptivity of a combustion mixture (CO2/H2O/N2/soot) based on narrow-band spectral data provided by RADCAL. Currently, it is the only model available which can predict the emissivity/absorptivity of a luminous combustion mixture with soot. For a non-luminous combustion mixture without soot, it has been demonstrated to be superior to the approach using Hottel’s chart (as outlined in standard heat transfer textbooks).

Details of the research are presented in Walter W. Yuen, “RAD-NNE T, A Neural Network Based Correlation Developed for a Realistic Simulation of the Non-Gray Radiative Heat Transfer Effect in Three-Dimensional Gas-Particle Mixtures”, International Journal of Heat and Mass Transfer, Vol. 52, pp. 3159-3168, June 2009.

RADNNET-SSPP (https://radnnet.makinoharashoko.me/RADNNET-SSPP-G) Calculation of Emittance/Transmittance of a CO2/H2O/N2/soot Mixture between Two Paralell Rectangular Surfaces with RADNNET

RADNNET-SSPP computes the exchange factor between two parallel rectangular areas with an intervening CO2/H2O/N2/soot mixture at arbitrary mixture conditions (temperature, partial pressure of the participating gas, and soot concentration) and wall temperature of the emitting surface.

The absorption of the mixture is computed using RADNNET which is a neural network developed based on narrow-band spectral data provided by RADCAL. The detail of RADNNET and its associated references are presented on the RADNNET website

A gray option of the code can be triggered by specifying a negative CO2 fraction. In the gray calculation mode, the total gas pressure is interpreted as a constant absorption coefficient with a unit of 1/m.

The zonal method is the basic computational scheme. The concept of point mean beam length (PMBL) is used to enhance the computational efficiency of the geometric integration. A detailed description of the PMBL concept can be found in the paper “Point Mean Beam Length, a New Concept to Enhance the Computational Efficiency of Multi-Dimensional Non-Gray Radiative Heat Transfer”

RADNNET-SSPD (https://radnnet.makinoharashoko.me/RADNNET-SSPD-G) Calculation of Emittance/Transmittance of a CO2/H2O/N2/soot Mixture between Two Perpendicular Rectangular Surfaces with RADNNET

RADNNET-SSPD computes the exchange factor between two perpendicular rectangular areas with an intervening CO2/H2O/N2/soot mixture at arbitrary mixture conditions (temperature, partial pressure of the participating gas, and soot concentration) and wall temperature of the emitting surface.

RADNNET-SG (https://radnnet.makinoharashoko.me/RADNNET-SG-G )

A Neural Network-Based Zonal Method to Calculate the Emissivity and Absorptivity of a three-dimensional cubical volume of gas/soot mixture.

RADNNET-SG computes the radiation heat transfer onto an arbitrary area at the base in an arbitrary cubical enclosure with a homogenous intervening CO2/H2O/N2/soot mixture at arbitrary mixture conditions (temperature, partial pressure of the participating gases, and soot concentration) and wall temperature of the emitting surfaces.

The computational scheme is identical to that used in RADNNET-SSPP-G and RADNNET-SSPG-G.

Significant Publications (related to RADNNET)

1. “RAD-NNE T, A Neural Network Based Correlation Developed for a Realistic Simulation of the Non-Gray Radiative Heat Transfer Effect in Three-Dimensional Gas-Particle Mixtures”, International Journal of Heat and Mass Transfer, Vol. 52, pp. 3159-3168, June 2009.

2. “Definition and Evaluation of Mean Beam Lengths for Applications in Multi-Dimensional Radiative Heat Transfer, a Mathematically Self-Consistent Approach”, ASME Journal of Heat Transfer, Vol. 130, No. 11, pp. 114507, Nov. 2008.

3. “Point Mean Beam Length, a New Concept to Enhance the Computational Efficiency of Multi-Dimensional Non-Gray Radiative Heat Transfer” Numerical Heat Transfer, Part B, Fundamentals, DOI: 10.1080/10407790.2020.1819686

4. “Development of the Concept of Mean Temperature in the Analysis of Radiative Heat Transfer in Inhomogeneous, Non-Isothermal, Non-gray Medium”, International Journal of Heat and Mass Transfer, Vol. 68, pp. 259-268, 2014.

5. “Assessment of Radiative Heat Transfer Characteristics of a Combustion Mixture in a Three-Dimensional Enclosure Using RAD-NNET (with Application to a Fire Resistance Test Furnace),” with W. C. Tam and W. K. Chow, International Journal of Heat and Mass Transfer, Vol. 68, pp. 383-390, 2014.

6. “On the Utilization of the Mean Beam Length Concept in the Evaluation of Radiative Heat Transfer in Isothermal Three-Dimensional Non-Gray Systems”, International Journal of Heat and Mass Transfer, Vol. 84, pp. 809-820, 2015

7. “Analysis of Radiative Heat Transfer in Inhomogeneous Nonisothermal Media Using Neural Networks“, W. W. Yuen, C. L. Chow and W. C. Tam, AIAA Journal of Thermophysics and Heat Transfer, May, 2016, (DOI: 10.2514/1.T4805).

8. “Numerical Study on the Importance of Radiative Heat Transfer in Building Energy Simulation” with W. C. Tam and W. K. Chow, Numerical Heat Transfer, Part A: Application, Vol. 69, No. 7, pp. 694-709, 2016. DOI: 10.1080/10407782.2015.1090822.

9. “OpenSC – an Open-source Calculation Tool for Combustion Mixture Emissivity/Absorptivity“, W. C. Tam and W. W. Yuen, NIST, Technical Note 2064, September, 2019.

10. “RADNNET-MBL: A Neural Network Approach for Evaluation of Absorptivity and Emissivity of Non-Gray Combustion Gas Mixture between Finite Areas and Volumes” W. W. Yuen and W. C. Tam, Proceeding of the Second Pacific Rim Thermal Engineering Conference, PRTEC-24081, Maui, Hawaii, USA, Dec. 2019.

11. “Assessment of Radiation Solvers for Fire Simulation Models Using RADNNET-ZM“, W. C. Tam and W. W. Yuen, Proceeding of the 11th Asian-Oceana Symposium on Fire Science and Technology, Taipei, Taiwan, October, 2018.

Significant Publications (related to Zonal Method, GZM, MACZM)

1. “An Efficient CPU – GPU implementation of The Multiple Absorption Coefficient Zonal Method (MACZM),” with B. Ghannam, M. Nemer, K. and El Khoury, Numerical Heat Transfer, Part B, Vol. 62, No. 6, pp. 439-461, 2012.

3. “Experimental Validation of The Multiple Absorption Coefficient Zonal Method (MACZM) In A Dynamic Modeling Of A Steel Rehating Furnace” with B. Ghannam, M. Nemer, K. and El Khoury, Numerical Heat Transfer, Part A, Vol. 58, No.7, pp. 545-563, 2010.

4. “Radiative Heat Transfer Analysis of Fibrous Insulation Materials Using the Zonal–GEF Method”, with G. R. Cunnington,, AIAA Journal of Thermophysics and Heat Transfer, Vol. 21, No. 1, pp. 105-113, Jan-Mar 2007.

5. “The Multiple Absorption Coefficient Zonal Method (MACZM), an Efficient Computational Approach for the Analysis of Radiative Heat Transfer in Multidimensional Inhomogeneous Nongray Media”, Numerical Heat Transfer, Part B, Fundamental, Vol. 49, No. 2, pp. 89-103, Aug. 2006,

6. “The Zonal Method – A Practical Solution Method for Radiative Heat Transfer in Non-Isothermal Inhomogeneous Media,” with E.E. Takara, Annual Review of Heat Transfer, Vol. 8, pp. 153-215, 1995.

7. “Development of a Generalized Zonal Method for the Analysis of Radiative Transfer in Absorbing and Anisotropically-Scattering Media” with E. E. Takara, Numerical Heat Transfer, Part B. Vol. 25, pp. 75-96, 1994.

Significant Publications (radiative heat transfer in scattering media)

1. “Determination of Optical Properties by Two-Dimensional Scattering” with A. Ma, I. C. Hsu and G. R. Cunnington, Jr., AIAA J. Thermophysics & Heat Transfer, Vol. 6, No. 1, pp. 182-183, 1992.

2. “Evaluation of Total Emittance of an Isothermal Nongray Absorbing, Scattering Gas-Particle Mixture Based on the Concept of Absorption Mean Beam Length” with A. Ma, ASME J. Heat Transfer, Vol. 114, pp. 653-658, 1992.

3. “Transient Radiative Heating of an Absorbing, Emitting and Scattering Material” with M. Khatami and G.R. Cunnington, Jr., AIAA J. Thermophysics & Heat Transfer, Vol. 4,No. 2, pp. 193-198, 1990.

4. “Development of a Network Analogy and Evaluation of Mean Beam Lengths for Multi-dimensional Absorbing/Isotropically Scattering Media“, J. Heat Transfer, Vol. 112, pp. 408-413, 1990.

5. “The Effect of Multiple Scattering on Radiative Transmission Measurements in a Two-Dimensional Absorbing-Scattering Medium” with W. Dunaway, AIAA J. Thermophysics & Heat Transfer, Vol. 1, No. 1, pp. 77-82, 1987.

6. “Calculation of the Geometric-Mean Transmittance in a Multi-Dimensional Absorbing and Anisotropically-Scattering Medium” with W. Dunaway, Intl J. Heat & Mass Transfer, Vol. 28, No. 8,pp. 1507-1515, 1985.

7. “A Limiting Approach for the Evaluation of Geometric Mean Transmittance in a Multi-Dimensional Absorbing and Isotropically-Scattering Medium“, ASME J. Heat Transfer, Vol. 106, pp. 441-447, 1984.

Significant Publications (in general radiative heat transfer)

1. “Superposition Technique for Radiative Equilibrium in Rectangular Enclosures with Complex Boundary Conditions” with E.E. Takara, Intl J. Heat/Mass Transfer, Vol. 33, No. 5, pp. 901-915, 1990.

2. “Analysis of Combined Conductive-Radiative Heat Transfer in a Two-Dimensional Rectangular Enclosure with a Gray Medium” with E.E. Takara, ASME J. Heat Transfer, Vol. 110, pp. 468-474, 1988.

3. “Rapid Heating of Gas/Small Particle Mixture” with K.Y. Wang, J. Solar Energy Engineering., Vol. 109, pp. 143-149, 1987.

4. “The Effect of Multiple Scattering on Radiative Transmission Measurements in a Two-Dimensional Absorbing-Scattering Medium” with W. Dunaway, AIAA J. Thermophysics & Heat Transfer, Vol. 1, No. 1, pp. 77-82, 1987.

5. “Calculation of the Geometric-Mean Transmittance in a Multi-Dimensional Absorbing and Anisotropically-Scattering Medium” with W. Dunaway, Intl J. Heat & Mass Transfer, Vol. 28, No. 8,pp. 1507-1515, 1985.

6. “Heat Transfer Characteristics of a Gas/Particle Mixture Under Direct Radiant Heating” with F. Miller and A.J. Hunt, Int. Comm. Heat & Mass Transfer, Vol. 13, pp. 145-154, 1986.

7. “Analyses of Two-dimensional Radiative Heat Transfer with a Gray Medium and Internal Heat Generation” with C.F. Ho, Intl J. Heat & Mass Transfer, Vol. 28, No. 1, pp. 17-23, 1985.

8. “Radiative Heat Transfer in a Rectangular Enclosure with Gray Medium” with L.W. Wong, ASME J. Heat Transfer, Vol. 106, pp. 433-440, 1984.

9. “Numerical Computation of an Important Integral Function in Two-Dimensional Radiative Transfer” with L.W. Wong, J. Quantitative Spectro. & Radiative Transfer, Vol. 29, No. 2,pp. 145-149, 1983.

10. “Evaluation of the Geometric Mean Transmittance and Total Absorptance for Two-Dimensional Systems“, J. Heat & Mass Transfer, Vol. 25, No. 7, pp. 1059-1071, 1982.

11. “A Simplified Approach to the Evaluation of Geometric Transmittance and Absorptance for Gas Enclosures“, ASME J. Heat Transfer, Vol. 103, pp. 808-813, 1981.

12. “Effect of Specular Reflection on Radiative Transfer with Anisotropic Scattering” with L.W. Wong, J. of Quantitative Spectro & Radiative Transfer, Vol. 25, pp. 427-434, 1981.

13. “Application of the P-1 Approximation to Radiative Heat Transfer” with D.J. Rasky, ASME Journal Heat Transfer Vol. 103, pp. 182-184, 1981.

14. “Heat Transfer by Conduction and Radiation in a One-Dimensional Absorbing, Emitting and Anisotropically-Scattering Medium” with L.W. Wong, ASME J. Heat Transfer, Vol. 102, pp. 303-307, 1980.

15. “A Simplified Approach to Shape-Factor Calculations Between General Three-Dimensional Objects”, ASME J. Heat Transfer, Vol. 102, pp. 386-387, 1980.

16. “A Successive Approximation Approach to Problems in Radiative Transfer with a Differential Formulation” with C.L. Tien, J. Heat Transfer, Vol. 102, No. 1, pp. 86-91, 1980.

17. “A Parametric Study of Radiative Transfer with Anisotropic Scattering in a One-Dimensional System” with L.W. Wong, J. of Quantitative Spectro & Radiative Transfer, Vol. 22, pp. 231-238, 1979.

18. “Approximate Solution of Radiative Transfer in One-Dimensional Non-Planar Systems” with C.L. Tien, J. of Quantitative Spectro & Radiative Transfer, Vol. 19, pp. 533-549, 1978.

19. “Radiation Characteristics of Honeycomb Solar Collectors” with C.L. Tien, Int. J. Heat and Mass Transfer, Vol. 18, pp. 1409-1413, 1975.

2. Fire Safety

In fire safety, Professor Yuen has focused his work on the effective of radiation on fire related phenomena such as flashover and flame spread. He also did work on using the Monte Carlo method for fire safety designs.

Significant Publications

1. “Heat transfer in a falling laminar liquid film with in-depth radiation absorption” with Jiann C. Yang, International Communication of Heat and Mass Transfer, pp. 47-53, 2018.

2. “Safety Consideration for Fire Shutters in Large Building Space“, with L. T. Wong, Journal of Applied Fire Science, Vol. 11, No. 2, pp. 195-208, 2003.

3. “A New Method for Selecting the Design Fire for Safety Provision” with W. K. Chow, Fire Science and Technology, Vol. 24, No. 3, pp. 133-150, 2005.

4. “A Monte Carlo Approach for the Design of Thermal Fire Detection system” with W. K. Chow, Fire Technology, Vol. 4, No. 2, pp. 93-104, April 2005.

5. “The Role of Thermal Radiation in the Initiation of Flashover in a Compartment Fire”, with W. K. Chow, International Journal of Heat and Mass Transfer, Vol 47/19-20 pp 4265-4276, Sept. 2004.

6. “The Effect of Radiative Heat Transfer on Thermal Ignition” with S.H. Zhu, AIAA J. Thermophysics & Heat Transfer, Vol. 3, No. 3, pp. 260-265, 1989.

6. “A Simple Calculation Scheme for the Luminous-Flame Emissivity” with C.L. Tien, The Sixteenth Intl Symp on Combustion, pp. 1481-1487, 1976.

3. Electronic Cooling

In the area of electronic cooling, Professor Yuen’s work had focused on the use of phase change material and high thermal conductivity foam to generate high heat flux cooling for electronic devices. Using graphite foam, he and his colleagues developed a Supercooler for an optoelectronic package operating with a heat flux of 400 W/cm2. He has also published works on heat transfer enhancement for conventional heat exchangers using pin fins and phase change material.

Significant Publications

1. “Development and Testing of an Energy Storage Material/Phase Change Material Enhanced Heat Sink” with G. Tu, W. Shi and H. Mak, Heat Transfer Engineering, 38:17, 1429-1438, DOI: 10.1080/01457632.2016.1255071 (2017).

2. “Design and Testing of a Graphite Foam-Based Supercooler for High-Heat-Flux Cooling in Optoelectronic Packages” with J. Tu, W.C.Tam and D. Blumenthal, Heat Transfer Engineering, Vol. 35, No. 10, pp. 913-923, 2014.

3. “An Assessment of Direct Chip Cooling Enhancement Using Pin Fin,” with Jianping Tu and Yishu Gong, Heat Transfer Engineering, Vol. 3, No. 10, pp. 1-9, 2012.

4. Two-Phase Flow/Nuclear Reactor Safety

In two phase flow, Professor Yuen has worked in the area of steam explosion with application to nuclear reactor safety. In additional to publishing extensively, he is the principle author of two DOE computer codes PM-ALPHA and ESPROSE.m, developed for the simulation of the premixing and explosion dynamics of a steam explosion.

Significant Publications

1. “PM-ALPHA: A Computer Code for Addressing Premixing in Steam Explosion“, with T. G. Theofanous, DOE/ID-10502, May, 1995.

2. “The Verification Basis of the PM-ALPHA Code” with T.G. Theofanous, S. Angelini, Nuclear Engineering & Design, Vol. 189, pp. 59-102, 1999.

3. “The Verification Basis of the ESPROSE.m Code” with T.G. Theofanous, K. Freeman and X. Chen, Nuclear Engineering & Design, Vol. 189, pp. 103-138, 1999.

4. “On the Existence of Multiphase Thermal Detonation,” with T. G. Theofanous, International Journal of Multiphase Flow, Vol. 25, pp. 1505-1519, 1999.

5. “Lower Heat Integrity Under Steam Explosion” with T.G. Theofanous, S. Angelini, J. J. Sienicki, K. Freeman, X. Chen, and T. Salmassi, Nuclear Engineering & Design, Vol. 189, pp. 7-57, 1999.

6. “On the Regime of Premixing” with T.G. Theofanous, S. Angelini, Nuclear Engineering & Design, Vol. 189, pp. 139-161, 1999.

7. “Experimental Simulation of Microinteractions in Large Scale Explosion” with X. Chen, R. Luo and T.G. Theofanous, Nuclear Engineering & Design, Vol. 189, pp. 163-178, 1999.

8. “Quantitative Radiography for Transient Multidimensional Multiphase Flows” with T. G. Theofanous, S. Angelini, X. Chen, R. Luo, Nuclear Engineering & Design, Vol. 184, pp.163-181, 1998.

9. “The Mixing of Particle Clouds Plunging Into Water” with S. Angelini and T.G. Theofanous, Nuclear Engineering & Design, Vol. 177, pp. 285-301, 1997.

10. “On the Constitutive Description of the Microinteractions Concept in Steam Explosions’‘ with X. Chen and T.G. Theofanous, Nuclear Engineering & Design, Vol. 177, pp. 303-319, 1997.

11. “The Prediction of 2D Thermal Detonations and Resulting Damage Potential” with T.G. Theofanous, Nuclear Engineering & Design, Vol. 155, pp. 289-309, 1995.

12. “Premixing-Related Behavior of Steam Explosion” with S. Angelini and T.G. Theofanous, Nuclear Engineering & Design, Vol. 155, pp. 115-157, 1995.

13. “The Probability of Alpha-Mode Contaminant Failure Updated” with T. G. Theofanous, Nuclear Engineering & Design, Vol. 155, pp. 459-473, 1995

14. “Multiphase Transients in the Premixing of Steam Explosions” with S. Angelini, E. Takara and T.G. Theofanous, Nuclear Engineering & Design, Vol. 146, pp. 83-95, 1994.

15. “On the Fundamental Microinteractions that Support the Propagation of Steam Explosions” with X. Chen and T.G. Theofanous, Nuclear Engineering & Design, Vol. 146, pp. 133-146, 1994.

16. “The Use of Fluorescence in the Measurement of Local Liquid Content in Transient Multiphase Flows” with H. Yan and T.G. Theofanous, Nuclear Engineering & Design, Vol. 141, pp. 315-318, 1993.

17. “FLUTE: FLUorescent Technique for Two-Phase-Flow Liquid-Fraction Measurements” with S. Angelini, W.M. Quam and T.G. Theofanous, Chemical Eng. Commun., Vol. 118, pp. 237-249, 1992.1.

5. Other Significant Publications

1. “An Efficient Algorithm for the Numerical Solution of the Transient Diffusion Equation with an Implicit Formulation” with L.W. Wong, Numerical Heat Transfer, Vol. 3, pp. 373-380, 1980.

2. “A Model of Metal Ignition Including the Effect of Oxide Generation”, Flammability & Sensitivity of Materials in Oxygen-Enriched Atmosphere, ASTM-910, Vol. 2, M. A. Benning, Ed., American Society for Testing and Materials, Philadelphia, 1986, pp. 59-77.

3. “Modelling and Data Analysis of the NASA-WSTF Frictional Heating Apparatus: Effects of Test Parameters on Friction Coefficient,” with S. H. Zhu, J. M. Stoltzfus, and F. J. Benz, Flammability & Sensitivity of Materials in Oxygen-Enriched Atmosphere, ASTM-986, D. W. Schroll, Ed., American Society for Testing and Materials, Philadelphia, 1988, pp. 172-187.

4. “Non-Fourier Heat Conduction in a Semi-Infinite Solid Subjected to Oscillating Surface Thermal Disturbances” with S. C. Lee, ASME J. Heat Transfer, Vol. 111, pp. 178-181, 1989.

5. “Application of the Integral Method to Two-Dimensional Transient Conduction Problems” with R.A. Wessel, ASME Journal Heat Transfer, Vol. 103, pp. 397-399,, 1981.

6. “Application of the Heat-Balance Integral to Melting Problems with Initial Subcooling”, Intl. J. Heat & Mass Transfer, Vol. 23, pp. 1157-1160.