TURBOMACHINERY
CENTRIFUGAL
PUMP
Cooling pump for a MotoGP engine
CLIENT
Motorcycle manufacturer
CHALLENGE
Improve the performance of the pump in the engine cooling system of a MotoGP
SUCCESS
Increase in cooling capacity
Reduction in vibration transmitted to the frame
Increase in engine life
A more reliable motorbike
01
CHALLENGE
A renowned motorcycle manufacturer asked us to study the pump in the engine cooling system of a MOTOGP, in order to improve its performance.
The motorcycle had overheating problems that put its reliability at risk: on a couple of occasions the rider could not finish the race, because engine failure followed too high a thermal stress. The machine also had cavitation problems at high RPM.
Our prime suspect was the cooling system: the actual flow rate was clearly not able to remove enough heat from the engine. The sizing of the centrifugal pump, however, seemed sufficient to compensate the pressure losses at the operating flow rates. We ran fluid-dynamic simulations of the pump under the correct installation conditions, to understand the cause of the problem.
02
SOLUTION
With the help of targeted CFD analyses based on validated models, we made the minimum number of modifications to the pump design necessary to ensure sufficient cooling capacity and a reduction in the vibrations transmitted to the frame.
The characteristic curve of the centrifugal pump at maximum rotational speed, 9000 RPM, was obtained by simulating six different stationary conditions, and compared with the curve of the cooling circuit. The CFD simulation at the operating point gave pressure values well below the cavitation pressure in some limited areas of the inlet.
The presence of a 90° curve before the intake was the main reason for the depression. It was not possible to modify the geometry of the intake duct, however, as that would have affected the entire engine and transmission design. We therefore had to improve the design of the impeller and intake duct, in order to minimise the areas subject to cavitation.
03
RESULTS
After the modifications we achieved an increase in cooling capacity and a reduction in vibration transmitted to the frame — a sign that the cavitation problem had been solved. The results were confirmed both by CFD simulations of the centrifugal pump and by test rides.
The resulting increase in engine life made the motorbike more reliable, allowing the rider to complete the next Grand Prix races without any problems.
