Numerical study on the effects of blocking ratio and spraying angle on the smoke flow characteristics of new energy vehicle fires in tunnels

•The electric vehicle fires are serious due to the fast flame propagation rate and higher smoke toxicity.•The effects of blocking ratios and key parameters of the water mist system in a horizontal and rectangular highway tunnel under longitudinal ventilation is investigated.•Spray angle does not affect the state of the smoke flow field.•The relationship between the cross-sectional size of the blocked vehicles in the tunnel and the spray angle is proposed.•A critical velocity correction model is proposed.