10.17634/154300-85 B Jia B Jia R Mikalsen R Mikalsen A Smallbone A Smallbone T Roskilly T Roskilly Frictional losses in free-piston engine and crankshaft engines Newcastle University 2018 Piston assembly friction Frictional force Free-piston engine 2018-01-01 00:00:00 Dataset https://data.ncl.ac.uk/articles/dataset/Frictional_losses_in_free-piston_engine_and_crankshaft_engines/10280855 The main friction mechanisms were identified to be the piston assembly including piston rings and piston skirt, valve train system, the crank and bearing system for the CSE, and the linear electric generator for the FPE. The frictional loss of each friction mechanism was estimated and discussed.