Effects of boundary-layer separation controllers on a desktop fume hood.
A desktop fume hood installed with an innovative design of flow boundary-layer separation controllers on the leading edges of the side plates, work surface, and corners was developed and characterized for its flow and containment leakage characteristics. The geometric features of the developed desktop fume hood included a rearward offset suction slot, two side plates, two side-plate boundary-layer separation controllers on the leading edges of the side plates, a slanted surface on the leading edge of the work surface, and two small triangular plates on the upper left and right corners of the hood face. The flow characteristics were examined using the laser-assisted smoke flow visualization technique. The containment leakages were measured by the tracer gas (sulphur hexafluoride) detection method on the hood face plane with a mannequin installed in front of the hood. The results of flow visualization showed that the smoke dispersions induced by the boundary-layer separations on the leading edges of the side plates and work surface, as well as the three-dimensional complex flows on the upper-left and -right corners of the hood face, were effectively alleviated by the boundary-layer separation controllers. The results of the tracer gas detection method with a mannequin standing in front of the hood showed that the leakage levels were negligibly small (≤0.003 ppm) at low face velocities (≥0.19 m/s).
a Department of Mechanical Engineering , National Taiwan University of Science and Technology , Taipei , Taiwan , Republic of China.
Rong Fung
RF
Huang
b Institute of Occupational Medicine and Industrial Hygiene , National Taiwan University , Taipei , Taiwan , Republic of China.
Jia-Kun
JK
Chen
c Graduate Institute of Applied Science and Technology , National Taiwan University of Science and Technology , Taipei , Taiwan , Republic of China.
Ching Min
CM
Hsu
a Department of Mechanical Engineering , National Taiwan University of Science and Technology , Taipei , Taiwan , Republic of China.
Shuo-Fu
SF
Hung
D000392:Air Movements; D016902:Air Pollution, Indoor / Q000517:prevention & control*; D004867:Equipment Design; D008348:Manikins; D016273:Occupational Exposure / Q000517:prevention & control*; D014691:Ventilation / Q000295:instrumentation
Flow visualization; fume hood; fume hood improvement; tracer-gas test