World speed record (4.94 knots)
First position in the general classification
First position for speed without propeller
First position for speed with propeller
Having already demonstrated our ability to perform well in each of the categories, we decided to go a step further and design a concept never seen before.
Omer 11 is therefore the creation of several months of work in order to push the limits of the manufacture of human powered submarines. It has the same hull shape has Omer X, thereby concentrating the team effort in other major elements such that the two drive modes, the mode control thereof and their manufacture.
Omer 11 is the first submarine to have two propulsion systems which it can interchange between races. The first system is a standard propeller propulsion system. It is fitted with precambered blades with variable pitch controlled from the on-board computer. It is also equipped with a propeller-less propeller system, similar to the one on Omer X. This system has been completely redesigned to reduce weight and reduce mechanical losses.
The propeller propulsion of Omer 11 was designed to be adaptive and aggressive, promising higher speeds than those obtained by the club before.
The design and manufacture of the aluminum tail cone, both ETS made, allows a more resistant part without sacrificing buoyancy. Indeed, the cone was 3D printed to be able to include cavities in its walls and offer a lighter design.
In addition of being a marvel of engineering, the aluminum cone also allows the use of the monopale. This blade, longer than normal and pre-cambered, reduces propulsion losses caused by turbulence in systems with several blades. Indeed, the water agitated after the passage of a first blade has the effect of reducing the efficiency of the second. By using only one blade, the losses are thereby reduced. The length of the monopale and its pre-camber then compensate for propultion losses which results in a highly optimized system.
The only disadvantage of the monopale is its couple. Indeed, the moment of force created at the start of the race causes an imbalance and causes the submarine to rock. This effect can however be easily corrected using sinkers on the pitch side.
Propulsion without propeller
With the different propulsion systems of Omer X, we noticed that the biggest problem was the non-constant torque felt by the pilot. Indeed, pedaling in Omer X was like pedaling on a rocky road with random bumps. Changes had to be made.
The final version of the Omer 11 non-propeller propulsion system therefore consists of four mirage blades and is equipped with a cam and spring system in order to accumulate and dissipate energy when it is necessary so that the pilot feels constant torque and can thus give more power.
WHERE IS IT NOW?
Omer 11 is still functional and is currently used during club presentations and demonstrations. It is also on display at the entrance to Pavilion D at the École de technologie supérieure de Montréal.