Peer Review

The Thermal Wizard

Material Detail page

Reviewed:: Feb 16, 2007 by Engineering

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Ratings

Overall Rating:

Content Quality:

Effectiveness:

Ease of Use:

Overview:: The thermal wizard is a set of java applets that contains an
abundance of useful information and tools for anyone teaching or working in the
thermal sciences. Unit converters, tables of material properties, and
calculators for both heat transfer and head loss coefficients are among the
items included.

The applets contained in the module can be used to simulate all three modes of
heat transfer: conduction, convection and radiation. The conduction calculators
can be used to calculate heat transfer and temperature gradients across a
multilayer plate, embedded plates and cylinders, and across contacting surfaces.
The convection calculator considers both free and forced convection from
simple geometric shapes. The radiation calculator can be used to determine
radiation heat transfer between two surfaces that are either parallel or
perpendicular. The applet can also be used to calculate head losses
for several simple duct elements.
Type of Material:: Java applet calculator
Recommended Uses:: Can be used in an introductory heat trasnfer course.
Technical Requirements:: Web browser that runs java applets.
Identify Major Learning Goals:: To deomonstrate the relationships involved in many elementary problems of heat transfer and air flow.

To learn how to use the rate equations of conduction, convection and
radiation to calculate heat transfer rates in systems of rectangular or
cylindrical geometry.

To learn how to find the head losses in piping systems.
Target Student Population:: Undergraduate students in engineering taking a heat transfer course.
Prerequisite Knowledge or Skills:: Konowledge of the rate equations for the three modes of heat transfer and
understanding of minor loss relations in piping systems.

Content Quality

Rating:
Strengths:: The site provides:

1) A very useful collection of unit converters
2) A wide collection of material properties
3) An array of useful online calculators

The unit converters provide conversions for nearly 40 units ranging from
acceleration to work. The user is free to select the units for both the original
property and the final property, and 5-10 sets of units are available for each
property.

Property tables are included for common metals, non-metals, gases, and liquids, with separate tables for air and water. Thermal conductivity, density, and specific heat values are included in all of the tables, and viscosity data are included
in the gas and liquid tables.

Calculators offered include conduction calculators for heat transfer through
multi-layer walls and cylinders, and heat transfer from several embedded objects
such as plates and cylinders. Convection calculators include forced convection
over plates and rods and natural convection from horizontal plates in different
orientations. Radiation calculators include radiation between parallel and
perpendicular rectangles and parallel circular surfaces. Finally head-loss
calculators are included to determine losses from duct inlets and outlets and
across screens and louvers.
Concerns:: None

Potential Effectiveness as a Teaching Tool

Rating:
Strengths:: Can be used as a demonstrative tool for teaching fuindamentals of heat transfer.
Each applet comes with an explanatory pop-up display of pertinent theory with
a link for additional information. The applets can be used to augment lectures
and to serve as tool for solving practice problems in class.

Each of the calculators offers the user a "Do You Want to Know More?" button
which, when clicked, brings up a full discussion of the topic at hand, including
references. These discussions are excellent from a pedagogical perspective and make this site very effective as a teaching and learning tool.
Concerns:: Unlike the unit converters, the remaining portions of the site employ SI units
exclusively. While not a major concern, it would be very useful if the user
could select either SI or English units for the various calculators.

Ease of Use for Both Students and Faculty

Rating:
Strengths:: The site is very easy to use by anyone at all familiar with online materials.
The menu items and buttons are all laid out in a convenient and intuitive
manner.
Concerns:: None

Other Issues and Comments:: Overall this is a very good calculator for learning how to calculate
temperatures based on the geometic relations and rate equations for the modes of
heat transfer. It is easy to use and for one to understand better the three modes of heat transfer.
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