Tuesday October 21, 2014 at 4:02pm
If you are designing a tank or product that has a cavity and you want to know the exact fluid volume (or mass) then here's how.
Whilst on support last week a customer emailed in to ask how he could calculate the volume of his fuel tank. When the geometry gets complicated then this can be a tricky calculation by hand - but why not get SOLIDWORKS to do the work for you?
There have always been a couple of ways to do this using the Combine tool or, for Flow users, the option to create the internal fluid volume automatically. However, in SOLIDWORKS 2014 there is a very cool feature that will do this with ease. It was one of the demos at the 2014 launch events, but with so many new tools and features to get to grips with, it is unsurprising that some get forgotten - until you need it.
Below is an image of a simple tank part. It has a large open area underneath and some openings where the outlet / inlet pipe would connect.
The new feature to use is called 'Intersect'. It appears on both the Surfaces and Features command managers. Essentially it intersects bodies, surfaces and planes and generates all the potential outcomes. The user can then select which he wants to keep and which to discard. It is similar to the Split feature but more sophisticated.
Before starting the Intersect feature you must create surfaces or planes that close the fluid volume. In the case of the tank I added a reference geometry plane on the underneath and used the 'Planar Surface' tool to fill up the holes at the pipe inlet. I did this on the inside of the tank for the bolt holes and the outside for the pipe hole. This will then include some of the pipe volume. Below is a screenshot of the filled holes ...
The Intersect tool is a doddle. Just select the tank body, the plane and 3 surfaces and select 'Intersect'. The result will be a number of bodies in the table. You can now choose which need to be kept (i.e. the region of the fluid) and which to be discarded. In practice this often means picking the ones to be discarded and the using the very useful 'Invert Selection' button.
Here is the finished fluid volume.
Now if I use the Mass Properties tool I can get SOLIDWORKS to calculate the exact volume.
By Andy Fulcher
Solid Solutions Management Ltd