Today is Wisdom Wednesday. A bi-weekly item in which we put a spotlight on one of our technological innovations. This week we will tell you all about our canopy. The canopy is the transparent dome on the solarcar through which the driver can see. A very important but also challenging part of the car! Our aerodynamics engineer Guido is responsible for the design of the canopy and will this week explain the challenges that come with the design and production of the canopy.
One of the biggest challenges with designing the canopy is arranging the amount of space which is necessary for all of the components in the car. For example, the driver needs the space to sit in the car, but the electrical components also need some space. When it comes to the driver, the space cannot be determined only by the size of the driver, but is also subject to regulations set by the organization of the Bridgestone World Solar Challenge. An example of one of these regulations is the ‘occupant space’, also known to us as the ‘crash rule’. This rule states that there must be a certain amount of movement possible for the driver within the canopy when seated. This to be sure that in the case of a crash, there are no parts sticking out into the occupant space which can be a risk to the safety of the driver.
Shaped for speed
The design of the canopy starts with an airfoil. This is the transverse section of the wing and needs to be formed as tightly around the required amount of space as possible. The canopy has to be as aerodynamic as possible, just like the rest of the car. Based on the wing, the canopy is shaped like a dome. With computer simulations, we can analyse and calculate how the dome must be shaped to achieve the best aerodynamic form.
Does size matter?
While forming the canopy, it’s not the size that matters, but it’s all about creating a shape with the least amount of drag. This often means that the canopy design looks bigger than what needs to be in it size wise. An example of this is the long ‘tail’ at the end of the canopy. This however makes sure that the flow is stuck to the surface for as long as possible, reducing the wake behind the car. The wake is turbulent flow which causes a lot of drag, which we don’t want. Luc, aerodynamics engineer during last edition, tells you more about it in the video below. The canopy also has an asymmetrical form. Due to it being an asymmetrical form, the air pressure stays the same on both sides of the canopy, which means better aerodynamics.
How it’s made
When the design for the canopy is finalized this needs to be produced. The canopy is milled with some reference lines on it, from a large piece of epoxyfoam; which we call the plug. After this a transparent plastic is carefully formed over the plug. This will eventually determine the shape of the canopy. Our header photo shows this process! The previously mentioned reference lines are now used to cut the front and rear part of the canopy from the plastic. When the production of the car shell is complete, the canopy will be glued to the carbon shell of the car.
- One of the biggest challenges with designing the canopy is arranging the amount of space which is necessary for all of the components in the car.
- While forming the canopy it’s not the size that matters, but it’s all about creating a shape with the least amount of drag.
- The reference lines of the canopy are milled from a large piece of epoxyfoam; which we call the plug. After this a transparent plastic is carefully formed over the plug, this is what will be the canopy!