Determination of fan design parameters for light-sport aircraft


  • Jan Klesa Czech Technical University, Faculty of Mechanical Engineering, Department of Aerospace Engineering, Karlovo náměstí 13, Prague 2, Czech Republic



ducted fan, electric propulsion, axial compressor


This paper is focused on the preliminary design of an electric fan for light-sport aircraft. Usage of electric motors brings some advantages compared to piston engines, especially small size and the independence of power on shaft RPM. A 1D compressible fluid flow model is used for the determination of the performace. The influence of various system parameters is analysed. Results for the case of the UL-39 ultralight aircraft are presented. Finally, input parameters for the fan design are determined according to this analysis. This can be then used as input data for the standard fan (axial compressor) design procedure.


Download data is not yet available.


M. Hepperle. Electric flight – Potential and limitations. Energy Efficient Technologies and Concepts of Operation (STO-MP-AVT-209), 2012. Accessed 2022-10-26,

Electric & hybrid-electric propulsion, 2022. Accessed 2022-10-26,

Rolls-Royce plc. Rolls-royce advances hybrid-electric flight with new technology to lead the way in advanced air mobility, 2022. Accessed 2022-10-26,

S. D. V. Weelden, D. E. Smith, B. R. Mullins. Preliminary design of a ducted fan propulsion system for general aviation aircraft. In AIAA 34th Aerospace Sciences Meeting and Exibit, 96-0376.

Letecká amatérská asociace ČR. UL 2 - Část I., 2019. Accessed 2022-10-26,

Deutscher Aero Club. Lufttüchtigkeitsforderungen für aerodynamisch gesteuerte Ultraleichtflugzeuge LTF-UL vom 15.01.2019 und Änderung vom 28.02.2019 (NfL 2-459-19), 2019. Accessed 2022-10-26,

N. A. Cumpsty. Compressor Aerodynamics. Krieger Publishing Company, 2nd edn., 2004.

R. O. Bullock, I. A. Johnsen. Aerodynamic Design of Axial Flow Compressors. NASA-SP-36. NASA Lewis Research Center, Cleveland, OH, 1965.

R. Theiner, J. Brabec. Experience with the design of ultralight airplane with unconventional powerplant. Proceedings of the Institution of Mechanical Engineers, Part G; Journal of Aerospace Engineering 232(14):2721–2733, 2018.

J. Hejna. Intake Desing for Experimental Fan. Master’s thesis, Czech Technical University in Prague, 2021. Accessed 2022-10-26,

S. Farokhi. Aircraft Propulsion. John Wiley & Sons, 2nd edn., 2014.

S. Albrig. Angewandte Strömungslehre. Akademie-Verlag, 5th edn., 1978.




How to Cite

Klesa, J. (2022). Determination of fan design parameters for light-sport aircraft. Acta Polytechnica, 62(5), 549–557.