Based on the test data

the simulation model of turbocharged diesel engine was established

and the adaptability research of 0～4000m plateau was carried out. The relationship between the performance of turbocharged diesel engine and the altitude variation of compressor performance was studied. The internal flow conditions of compressor at different altitudes were studied

and the reasons for the decline of compressor efficiency were analyzed. The results show that the power

torque and fuel consumption rate of diesel engine decrease under high altitude conditions. The inlet flow decreases

the pressure increases

the compressor pressure ratio increases

and the efficiency decreases. The pressure in the low pressure region of the relative total pressure on the compressor meridian plane is small

and the high entropy region between the tip clearance and the impeller outlet increases and the range is in advance. As the transonic flow region increases

the shock wave loss increases

the tip clearance flow is strengthened

the leakage loss increases

the mainstream of the trailing edge of the splitter blade is mixed with the low speed leakage flow

the wake area

the mixing loss

and the internal loss of the compressor impeller increase

so the compressor efficiency is reduced in the plateau environment.