Study on Tunnel Air Curtain Insulation System for Cold Areas

Table 5

Measured data and calculated values of air curtain on main slope.

External temperature/°C	External wind speed/(m/s)	Wind speed after the air curtain starts(m/s)	Measured barrier efficiency/%	Calculated barrier efficiency/%	Error/%
4∼8	2.28	0.63	72.2	77.79	7.7
0	3.27	1.51	54.0	54.24	0.44
−10	5.60	3.05	45.5	31.67	30.4