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[FAQ]

This error message shows that there is a large amount (>0.9) of volume fraction being transported into or out of an Euler cell in a single time step. Autodyn prints this message in order to prevent potential numerical error by limiting the amount of transported material. The following instructions will help you to solve this problem: 1. Use Internal Energy Transport. This is set in the Controls panel, under Transport, by selecting internal for the ALE/Euler Energy option. The default in AUTODYN is Total Energy Transport. In Euler shaped charge calculations where the detonation products escape into a void at high speed, a better result will be achieved using internal energy transport as this provides a more accurate determination of the internal energy in a cell, which in turn is used in the explosive equation of state. 2. Use large relative density cutoffs 1.0E-4 instead of default 1.0E-6. This is set for each material and can be changed in the Material panel by selecting the relevant material from the list and pressing the Modify button. The escaping detonation products are typically at very low density. It is useful to limit the diffusion of extremely small masses by increasing this cutoff value. 3. Use a Maximum velocity cutoff of ~10,000 m/sec. Very small masses of explosive escaping into Void can sometimes achieve unrealistic velocities. This should be limited by setting the Maximum velocity cutoff in the Controls panel under Global Cutoffs.