Application Note: Secret Agents
It's tempting to think of scalars as "secret agents" because many of our users haven't discovered the variety of ways they can be used. Reading the articles in this Newsletter should give you some ideas. In Time Travel the discussion covers ways scalars may be used to record different types of time intervals. The article Making History explains how scalars may be used for tracking a wide variety of phenomena such as surface reactions, casting defects, and air entrainment. And in Taking Charge there are suggestions for simple ways in which scalar agents can be used for debugging purposes or for producing derived quantities or other non-standard data.
In this article we discuss other novel uses for scalar. For example, there
is a new user customization (see the FLOW-3D User
Tech Support section)
for introducing electromagnetic forces in continuous casting that uses scalars
to record the components of magnetic induction. A simple modification involving
a scalar variable has also been devised for the lost-foam casting model to add
a variable foam density.
Using the time-of-fill feature in the program (a scalar agent) a user discovered that it provided information about lapping phenomena in high-pressure die casting. Lapping occurs when metal begins to fill a region, then stops for a time before finally filling completely. If the time-of-fill plots show locations with large gradients in the fill time, then those locations are also where lapping is probably occurring, a situation usually accompanied by a defect.
A scalar variable could also be used to record small deflections of a solid wall. The change in deflection would then be used to define a local volumetric source or sink for fluid. Or a scalar could be used to track solute content in a liquid or to count the number of discrete particles residing in a control element. Why not use a scalar agent to record the time that some quantity has a value within a prescribed range?
It should be no secret that a little imagination coupled with the scalar features in FLOW-3D gives you the means to take an undercover look at complex flow phenomena.