Last Updated: 6/1/2009
Free Excel/VBA Spreadsheets for Heat Transfer
(and Fluid Mechanics, PDE's, Thermodynamics and
Numerical Methods, too)
If you click on any of the entries below, that Microsoft Excel workbook will be downloaded to your computer. Each of them involves at least one module written in Visual Basic for Applications (VBA), Excel's macro language. All were written under Windows, but should work under MS Office running on a Macintosh. Earlier versions of MS Office on both platforms may not support all features used in these workbooks. Improved versions of several of these spreadsheets as well as several others will be included on the Heat Transfer Today CD-Rom when it is published.
Disclaimer
No warranties, expressed or
implied, are made that these programs are free from error, or are consistent with
any particular standard of merchantability, or will meet your requirements for
any particular application. These programs should not be relied on for solving
problems whose incorrect solution could result in injury or lost property. If
you use these program in such a manner, it is at own risk. The author disclaims
all liability for direct or consequential damages resulting from your use of
these programs, i.e., SOFTWARE THAT IS FREE HAS NO GUARANTEE!
Each of these Excel workbooks
contain at least one macro written in Visual Basic for Applications, so that
when you open one of them in Office 2003 and earlier you will probably see a
warning like, "[filename] contains macros. Macros may contain viruses. It
is always safe to disable macros, but if the macros are legitimate, you might
lose some functionality." Then you are given the choices: "Disable
Macros", "Enable Macros" and "More Info". In the case
of these spreadsheets, you must select "Enable Macros" or they will
not work at all! (If you not even offered this choice, then your security is
probably set at "High." You must have your security level in Excel
set at "Medium" first, before you even open the workbook. This allows
you to "choose whether or not to run potentially unsafe
macros.") In Office 2007 you
will get a message on the command line and can enable the macros there.
My virus checker is set to update automatically every day (yours should be too!). You should scan these materials (and anything else containing macros you download from the Internet) before opening them, but then you MUST enable macros!
Two-Dimensional, Steady-State Conduction (Updated: 2/16/09)
This workbook evaluates the analytical solution for steady-state conduction in a unit square with one boundary held at a different temperature than the other three and returns a raised contour plot of the results. This particular problem is used frequently to demonstrate separation-of-variables as a solution technique for PDE's. The user can change the number of terms to be included in the evaluation of the infinite series. A new, second worksheet animates the process of adding terms to the series. Quite a few are needed in this particular problem to get a good solution here - because of the discontinuity at two of the corners and the animation shows the Gibbs phenomenon clearly.
Periodic Conduction in a Semi-Infinite Body (Updated: 6/18/07)
This one "animates" the analytical solution for transient conduction in a semi-infinite body subject to a periodically varying temperature at the exposed face. The input parameters used for the plot shown correspond to the annual temperature cycle in the ground (about 3x10E7 seconds), but may be readily changed.
Planck's Law (Updated: 4/9/09)
This workbook computes and displays the spectral blackbody emissive power for a number of source temperatures. This new version also allows the user to display the spectral blackbody emissive power for a particular temperature and evaluates the integral over a wavelength range selected by the user (replicating the tabulated blackbody radiation functions). (See the cyan-colored lines in the figure below.) Another sheet is this workbook includes tabulated data for the spectral transmissivity of two types of glass, one of them a standard glass, the other a "low-E" (low-emissivity) glass. The function for blackbody emissive power, this tabulated data and Simpson's Rule may be used to find the total transmissivity of the two glasses.
Radiation View Factors (Updated: 2/21/09)
Air-Water Properties (Updated: 3/13/09)
Five state and transport properties of air and seven of water, all of which are functions of temperature, are included in this module. These user-defined functions may be invoked in a worksheet exactly as are the supplied functions (sine, cosine, sum, etc.) and allow the design engineer to do multiple calculations readily without cumbersome table lookups. These functions were developed for use in the Sweaty Runner and Lister Bag projects. A discussion of the former project assignment may be found in: Ribando, R.J. and Galbis-Reig, V., "Convective Heat and Mass Transfer from a Runner Using Some Modern Spreadsheet Features," Computers in Education Journal, Vol. VIII, No. 4, Oct. - Dec. 1998, pp. 22-28.
As with all items in the HTT software collection, the user is urged to verify the accuracy of these property functions before using them. The NIST Chemistry WebBook is an excellent resource.
Solution of Blasius Equation (Updated: 11/22/05)
This workbook performs a numerical solution of the Blasius equation for flow in a laminar, self-similar, flat plate boundary layer. The Runge-Kutta integration scheme and shooting algorithm used to solve this third-order, non-linear, ordinary differential equation were taken from An Introduction to Computational Fluid Mechanics by C.Y. Chow and embellished with Excel graphics. In the 5/11/04 version tabulated results from a classical source (Howarth's results as reported in Schlicting) were added for comparison with the current solution.
Internal-Flow Convection Correlations (Updated: 3/16/09)
This workbook computes the
Nusselt number for forced convection in a circular pipe as a function of the
Reynolds (based on diameter) and Prandtl numbers (and where appropriate one or
two other parameters). It includes subroutines for laminar, transition and
turbulent flows, and for liquid metals. Results for a range of Reynolds and
Prandtl numbers are show in this plot. This spreadsheet was developed to aid in
verifying our internal flow module
This workbook includes three
separate demonstrations of Gauss-Seidel (Liebmann) iteration for the solution of
systems of linear equations. The first one, shown in the figure, demonstrates
using G-S to solve the system of linear equations arising from the
finite-difference discretization of
This workbook is intended for use
as demonstrations in an introductory course in Computational Fluid Dynamics
and Heat Transfer at the introductory graduate and advanced undergraduate
level. It consists of two sheets. On the first one the user can select one of
five separate differencing schemes for the transient, one-dimensional advection
equation and input the Courant number. Numerical diffusion and dispersion are
vividly illustrated as the initially-square wave is advected across the plot.
Differencing schemes included are simple upwind, weighted upwind, Quick (third
order), Flux-corrected Transport (FCT) and Total Variation Diminishing (TVD).
The second sheet
demonstrates use of the upwind and weighted upwind schemes in two dimensions. A
cone representing a passive scalar is advected for one orbit in a velocity
field corresponding to solid body rotation. The resulting distribution is plotted
at 22.5o intervals so as to give the effect of animation.
Projectile Motion (Updated: 1/2/04)
Elliptic Grid Generation (Updated: 3/12/04)
One-Dimensional Compressible Flows (Updated: 6/15/07)
This first workbook includes
worksheets for: (1) Isentropic flow with area change, (2)
The second workbook is for
oblique, planar shocks. The user
will have to become familiar with Excel’s Solver Add-in in order to use this
workbook.
Velocity Triangles (New: 10/23/08)
This workbook allows the user to
create velocity vectors with heads using Excel's charting (not drawing) capability.
The user invokes the supplied VBA macros to add the arrowheads. They are scaled
proportionally. These macros are very helpful in drawing velocity triangles, as
used in the analysis and design of turbomachinery.
Vortex Motion above a Runway (Updated: 7/8/2003)
This spreadsheet is an Excel/VBA
translation of a Fortran program from C.Y.Chow's An Introduction to
Computational Fluid Mechanics. The program tracks the motion of wingtip
vortices and shows their motion as induced by each other and influenced by the
nearby ground and the ambient crosswind. The user can change the crosswind
speed, wingspan, mass of the aircraft and aircraft velocity and watch the
impact on the subsequent motion of the vortices. The simple model includes no
dissipation of the vortices, but it is well known that trailing
vortices may be long-lived and dangerous to following aircraft.
1976 U.S. Standard Atmosphere (Updated: 11/14/2003)
One-dimensional Wave Equation (Updated: 3/21/2008)
Solution
of Linear Equations (Updated:
1/11/06)
Brayton Cycle
Gas Turbine Cycle Template (Updated 5/12/2009) – with sound and
regeneration!
Rankine Cycle Steam
Turbine Cycle Template (Updated 5/12/2009)
Otto Cycle
Spark-ignition, Internal Combustion Engine Template (Updated 5/12/2009) –
with sound!
Diesel Cycle
Compression-ignition, Internal Combustion Engine Template (New 5/28/2009)
HTTdemosub.xls
A spreadsheet demonstrating a lot of features of Excel and VBA (New 5/29/2009)
This one includes buttons, scrollbars,
functions, subroutines, named ranges and even narration.
General Reference on Use of
VBA with Excel (VBAPrimer.pdf):
Ribando, R.J., "An
Excel/Visual Basic for Applications (VBA) Primer," Computers in
Education Journal, Vol. VIII, No. 2, April-June 1998, pp. 38-43. A version
of this article updated for Excel 2007 may be found here.
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