These online calculation pages implement heat transfer models developed by the Microelectronics Heat Transfer Laboratory at the University of Waterloo. These models are accessed through a CGI interface and require the use of a forms-capable browser. New models will be added to this site as soon as they are completed.

• Natural Convection Model for Circular and Square-Finned Annular Heat Sinks
  Based on the Ph.D. research of C.S. Wang, this model predicts heat transfer from natural convection horizontal annular heat sinks. The online model incorporates both fin efficiency and radiation functions.
• Natural Convection Model for Rectangular Heat Sinks
  This model predicts heat transfer from natural convection rectangular heat sinks. The online model incorporates a fin efficiency function, and allows for both single and back-to-back configurations.

• Spreading Resistance Calculator for Circular Sources on Compound and Isotropic Disks
  Calculates the thermal spreading resistance for a circular source on an isotropic and two-layer circular disk, semi-infinite circular cylinder, or half space.
• Spreading Resistance Calculator for Isoflux Rectangles and Strips on Compound Flux Channels
  Calculates two- and three-dimensional thermal spreading resistance for isoflux rectangular and strip sources on an isotropic and two-layer rectangular disk, a semi-infinite rectangular cylinder, or half space.

• NEW! WebMETA Online Demo
  Based on the successful META (MicroElectronic Thermal Analyzer) program, this application allows the user to define a circuit board, then outputs graphs of temperature, velocity, heat flux and more. This demo has limited features, but is fully functional. Must have Netscape 4.0 or greater.
• Coming Soon! Effective Conductivity Model for Rectangular Heat Sources
  This model predicts effective conductivity from a rectangular heat source, based on the composition of the substrate and boundary conditions on the source. Must use Netscape 3.0 or greater.

• Thermal Fluid Properties Calculator
  Properties of air, Ar, N₂ and H₂ calculated based on correlations developed by F McQuillan. Properties of CO₂, H₂O(l) and the ethylene glycols are based on the correlations developed by Tom Lemczyk. The calculator takes the temperature of the fluid as input and outputs an array of properties at 1 atm.

• Special Functions Calculator
  Calculates special mathematical functions, including Gaussian error and complementary error functions, gamma functions, and Bessel functions of integer or fraction order