Top Shell Area Discussion

**These are notes and takeaways from a conversation between Jason and Advait

Advait has a calculator that can calculate weight of the top shell, given different weights.

https://docs.google.com/spreadsheets/d/1KoeBqx8UkJFtk7HJsVcS61Oh_bHfv17oKRhwfuexZYM/edit?gid=0#gid=0

Formula for weights: (((array_area+2.5) * 4 * 273 + (array_area+2.5) * 4 * 273 * 1.3)/453.6) + 50.11 + ((((0.085017361111*(array_area+2.5))/3783.88) * 48.0554) *1000 + (0.085017361111*(array_area+2.5)) * 4 * 273 + (0.085017361111*(array_area+2.5)) * 4 * 273 * 1.3)) / 453.6

• This formula is long, overcomplicated, and incomplete. Jason has a much better formula, or better yet, just use the sheet

Top shell area calculations

• Daybreak total top shell area (length * width) was ~6.75 square meters.

• The array area was 4 square meters.

• Assuming we optimize slightly(put cells closer together and put a few cells in more areas like next to the canopy) we are assuming that we will lose about 2.5 square meters from the length time the width.

• length*width - 2.5 = total array area

Width

• The width of the pickle doors is 69 inches. We want to have at least an extra inch to get the mold out of the doors.

• We want to have 3 inches on each side of the mold in order to allow for vacuum bag, a lip for carbon fiber, and to make sure that that lip wont break

• Open

  

• This limits our width of the topshell to 62 inches, and that is the maximum number

Length

• our limit for the length of the car is our working area

• The max length for our mold given working area is 190 inches

Area

• 190*62 is 11780, which is our max area in square inches.

• In square meters our maximum top shell size is 7.6 square meters

• Using our loss of 2.5 square meters due to canopy, area with no cells, and curved front topshell

Final Thoughts

• I (Jason) think we are gonna end up goin with the max top shell size that we can, and then aerodynamics goal will be to reduce that 2.5 square meter number as much as possible in order to try to get 6 square meters

  • this could mean a rectangular topshell, adding cells in areas we previously havent(next to canopy), or maybe even adding cells on a canopy.