[yanhua.li]

hello all,

recently, i do a test of die casting of a part and then simulation correlation.

1. formal production condition. there is a piston and sleeve in the inejction machine. when melt fluid injection to sleeve, the piston moving and finally pull the fluid to cavity. moving distance is 500mm for example for complete filling.

2. short shot of formal production condition. in order to correlate the simulation of FLOW3D with test, we do short shot test of different moving distance which is less than the completed one (500mm),such as 380mm,400mm,420mm......480mm. The test samples are get for comparison.

3. set the simulation of short shot same as test. we set the moving object stop at the according time/distance. for example, when we simulate 400mm one, it moving from 0s to 0.92s, and we set 0 velocity at 0.920001s. the finish time is enlarged to 1.5s due to inertia of fluid, finish condition is filling fraction 0.9999.

The question is, the results of simulation are different. filling fraction is smaller than test result. and the fluid continue to flow after 0.920001s and flow everywhere, finally sink due to gravity.


in test, after 0.92s, the fluid continue to flow too, but it cool down fast to resist the flow of fluid.

my question is that, what is the problem? how to simulate the correlation to test?