Experimental investigation and numerical simulation of small-volume transverse-flow air curtain performances

Air curtains have been thus far widely applied in thermal-insulation and dust-isolation sites. However, in some application scenarios that have strict constraints on the volume of the air curtain generator, the relations of the volume lower limit of the generator with the uniformity of the formed air curtain were poorly investigated. This study focused on small-volume transverse-flow air curtain generator, performed experiments and FLUENT numerical simulations for investigating the effects of three structural parameters, namely the cross-sectional area of the air curtain generator, the air supply groove and the diversion blades, on the uniformity, diffusivity and deviation of the formed air curtain. Results reveal that the cross-sectional area of the air curtain generator can directly affect the uniformity of the formed air curtain. By increasing the cross-sectional area, the static pressure difference in the air curtain generator along the full-length direction can be reduced and the uniformity of the air curtain can be enhanced. Under the premise that the constraints of the volume upper limit of the air curtain generator had to be satisfied, the optimal cross-section diameter of the air curtain generator was determined to be 110 mm. The use of the air supply groove with an appropriate length can effectively suppress the turbulence of the airflow at the outlet, weaken the entrainment effect of the jets on surrounding air and make the formed air curtain more concentrated. This study proves that an air supply groove with a length of 35 mm can satisfy the present requirements. In addition, the diversion blades can play the role of mechanical diversion so as to strengthen the turning of airflow and cope with serious deviations of the air curtain. In this study, using diversion blades with a spacing of 60 mm, the formed air curtain was nearly horizontal.