Dear,

I've been busy building this car in Rhinoceros 4 for a school project (I also built my own wind tunnel) but now I want to put this car in the virtual Solidworks wind tunnel.

- But it keeps on saying that my car has to become a body, but how to do that?
- How to calculate the Drag coefficient with Solidworks? The formula for the Drag coefficient is: http://en.wikipedia.org/wiki/Drag_coefficient

I can also calculate it myself but then I've got to know:

- the speed (i know you can adjust that, and i know how to)
- the density of the air (i do also know that)
- the reference area (i don't know how to do that)
- the force of the drag (i don't know how to do that either)

This is the car: https://fbcdn-sphotos-d-a.akamaihd.net/hphotos-ak-prn1/857430_10200258026206396_48873402_o.jpg

Thank you very much!

Wesley

Hi Wesley, first things first, check out the tutorial B2 called cylinder drag. It has everything you need. I would also check out the solidworks customer portal KB to get more information about how to set this up in flow. Regarding the questions you have:

1. your model needs to be a solid, it can't be a surface model. once you've imported it into solidworks, run an import diagnostic on it and then investigate it for any openings. fill those openings with additional surfaces and use the knit feature to knit them together and the option "form a solid" to make it a solid. if flow can't find the solid, you can't run the analysis. you may have to post the model if you need more help beyond there.

2. drag force. create a surface goal where you select all the faces of your solid. the goal should be force in the direction of drag. (usually X direction)

3. drag coeffiicient. create another equation goal where you use the equation you've referenced. the reference area is described in the article, it is the frontal area. if you create a sketch of the overall frontal shape of your model and then create a flat surface, you can use the measure command to get that figure.