The Solidification Modulus Explained

The design of feeding systems is often aided by a physical solidification simulation. This approach can be time-consuming because the concept is usually optimized iteratively. As a direct method, on the other hand, every foundryman is familiar with the use of what is known as the solidification modulus. For complex castings, however, manual calculation of the modulus by decomposition into basic bodies is often too cumbersome. With a modern, software-based modulus computation, the advantages of both methods can be combined without suffering from their disadvantages.

[@alfonso444able]

excellent content and really well explained

[@mw1st]

What''s the value of the constant K?

[@Visiometa]

The constant K varies depending on the metal, molding material, temperature and other process variables. There are many ways to find the value of K for your specific process, see for example: en.wikipedia.org/wiki/Chvorinov%27s_rule - Visiometa internally uses a very different approach though, which is also mentioned in the video: we perform an automatic calibration step, which is a special pre-simulation to determine K such that the resulting modulus is comparable to geometric computations (e.g. for the feeder size).

[@andrewmartin4258]

That's for calculating the time of solidification. If you only care about ensuring the solidification proceeds from the intended casting back toward the feeder (so shrinkage will be in the feeder and not the casting) all you really have to do is insure the modulus (volume/surface area) increases progressively toward the feeder.
Here's an amateur description: ruclips.net/video/4uRtHrfN5MU/видео.html