Velomobile Frontal area

I finally have measured the frontal area of the new shape and the result has been good as the frontal area for this new shape is 0.36m2.

Calculating the CdA is now 0.36 x 0.21 (Cd) = 0.0756 CdA.
I can calculate using this excellent calculator power outputs and speeds for Veloci-velomobile. The graph below shows that for a modest 150W of power  a speed of  approx. 46 km/hr can be attained. I used 150W because this is what a untrained but fit cyclist could acheive for any length of time.

I also found that smoothing my final shape did not make any real difference to the Cd factor, at the most  it would have changed it by 0.1 so it is best to leave it as is. Now to build the models and then the real thing!

Velomobile aerodynamics final design

After re-drawing the bodyshell to fit the exact dimensions required I have found that the CdA figure has dropped to 0.081 Here is a few images of latest and final renderings before I make a full size working prototype.

This is a great result as I had thought that anything 0.10 or less would be adequate. My goals for the design have been reached with the low drag co-efficient, the low weight due to the construction in coroplast/corflute and I think I have achieved a a good looking design which is important for consumer acceptance.

I have been reading a lot about vehicle & chassis design and one thing really stood out to me was the way the automobile industry goes about designing a new vehicle as they take a very different approach.
Their most important criteria is asthetics. This is a basic overview of the design process...

1. Draw-up concepts
2. Choose a concept
3. Refine the concept
4. Larger scale concept produced concept adjusted to fit people and parts
5. Adjustments made to fit chassis platform and suspension
6. Body changes for aerodynamics
7. Prototypes built andtested, changes made
8. Production readying

Again the auto industry starts by defining the design by its appearance, designing a velomobile in such a way would lead to a vehicle that would not perform as expected. The design process for a velomobile and indeed Veloci-velomobile has been...

1. Application definition - lightweight, aerodynamic, single occupant, human powered vehicle
2. Chassis and suspension design - lightweight, stiff, independent suspension
3. Aerodynamically designed to envelop rider and chassis - again lightweight
4. Development of the entire design to make it user friendly and asthetically pleasing

So the design process is quite the opposite to the auto industry approach, I think I have achieved my goals in this design. Please feel free to comment.

Velomobile Kit? or Retro-fit?

With the Veloci Velomobile method of body construction it will possible to scale it to fit a wide range of different recumbent trike chassis.

This is already been done by other manufacturers with the Borealis velomobile as well as the Ocean Challenger .These are both fine examples of fitting bodyshells to existing recumbent trikes. The drawback is that they are quite heavy (32-36kg) and still relatively expensive.

Veloci Velomobile would weigh in at 20-23kg depending on the trike used as the chassis. This would be a great option for someone who already owns a trike and wants to have a cost effective way of converting their recumbent trike to a velomobile. The estimated cost for a retrofit to an existing trike chassis would be $US = 1000 or Euro = 780.

This is only one option as a custom designed chassis would have less compromises and maybe even be lighter! I have built three recumbent trikes - two with rear suspension, with the lightest being 13.5kg and the others 15-17kg so in theory Veloci Velomobile could be as light as 18-20kg complete!