An Impeller Aerodynamics Study

A research project involved a range of aerodynamic simulations for a new generation electric flight design. The study focused on optimizing the efficiency of multirotor three-bladed propellers within impeller ‘barrel’ geometry with further design-for-manufacturability optimisation.

A customer involved in new generation flight design contacted EnCata, upon conducting a series of bench tests of his three-bladed propellers (both single and twin-rotor), seeking to optimize the efficiency.

Such propellers, embedded in a stationary impeller, are designated to increase the air pressure within a ‘barrel’ and sometimes called “Bartini well”.

EnCata’s simulation engineers faced a task where the engine and three-bladed props were pre-defined, and one needed to come up with optional impeller shape and interprop distance. Firstly, the research team had to build the simulation model with adequate accuracy in order to verify the experimental data. Much effort was put into the validation of the testing procedures, in order to reproduce test bench results. While single-prop set-up is somewhat easy to optimize, the twin-rotor design required optimization for both the iterpropeller distance and ‘barrel’ shape / wall-tip separation. Upon running a large set up stationary aerodynamic simulations, the EnCata team came up with optimal rotor positioning and measured the max efficiency of the set-up with two propellers.

Further work encompassed DFM works to enable 3D-printing of the new impeller walls (the impeller is a rather large part, nearly 0.6 meters in diameter), so a 3D model had to adopt the assemblability, light ‘honeycomb’ structure (to reduce weight) without compromising structural rigidity.

The customer left EnCata with the definite answer how to position the multirotor props within his impeller, which was then ready for flight demonstrator. Our research is now incorporated into the customer’s flight design program.

Overall, the startup enjoyed the following services:

  • CFD numerical simulations
  • Applied research
  • CAD modelling (DFM)