To investigate the characteristics of contamination on different parts of insulator shed for electric multiple units（EMU）

a computational fluid dynamics（CFD）model of the contamination characteristics is built by dividing the shed into windward side

leeward side and crosswind side. The relations of the mass deposition rates of the three parts of the insulator shed with the contamination particle size and the wind speed are analyzed

and the differences of the mass deposition rates are compared. Simulation results show that: 1) with the increase in particle size

the mass deposition rates of windward side and crosswind side increase

but the mass deposition rate of leeward side decreases;2) the particle size has a great impact on the relationship between the mass deposition rate and wind speed

e.g. when the particle size is larger than 10 μm

the mass deposition rates of windward and crosswind sides ascend while the mass deposition rate of leeward side keeps zero with increasing wind speed

and the mass deposition rate of windward side is larger than that of crosswind side for same particle size and wind speed

however

there is no such rules if the particle size is smaller than 10 μm.