Feed paths and hot spots computation based on a time gradient method in casting

The aim of the present work is to calculate feed paths and hot spots by the time gradient method, which is based on the fact that the fastest solidification direction is the direction of temperature gradient. The energy conservation equation was solved coupling with N-S equation. The temperature field calculated under the circumstance of taking fluid flow into consideration has been compared with the experiment results in a step casting. Feed path is computed by tracking the direction of the time gradient in each calculation during the solidification process. Effects of the liquid metal flow on the calculation results of feed paths and hot spots have been discussed in detail in a “T” shape casting. An experiment has been done to validate the accuracy of the proposed model. The originating points of the feed paths indicate hot spots that manifest as shrinkage defects. And the numerical as well as experimental validations demonstrate the effectiveness of time gradient method for feed-path calculation.