Experiment determining pressure loss reduction using a shaped round exhaust hood

• Published in: Building and environment Vol. 190; p. 107572
• Main Authors: Logachev, K.I., Ziganshin, A.M., Popov, E.N., Averkova, O.A., Kryukova, O.S., Gol'tsov, A.B.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.03.2021; Elsevier BV
• Subjects: Boundary layers; Computational fluid dynamics; Contaminants; Drag coefficients; Drag reduction; Equipment purchasing; Exhaust hood shaping; Exhaust hoods; Food service; Local drag coefficient; Local exhaust ventilation; Loss reduction; Natural experiment; Noise pollution; Noise reduction; Pressure; Pressure loss; Reduction of power consumption; Local exhaust ventilation; Local drag coefficient; Reduction of power consumption; Exhaust hood shaping; Natural experiment
• ISSN: 0360-1323; 1873-684X
• DOI: 10.1016/j.buildenv.2020.107572

In this study, we experimentally determined the local drag coefficient (LDC) of a round exhaust hood that was improved with different shaped inlet sections along the boundaries of the vortex zones occurring in the flow at the inlet of an exhaust hood. The LDC measurements were performed using two methods. The first method used a micromanometer and pneumometric tube to determine the LDC with and without considering frictional losses. Meanwhile, the second method determined the LDCs using the pressure and velocity distributions in the boundary layer with specially designed pressure miniprobes. The experimental and numerical results show that it is possible to achieve a drag reduction of more than 90% by shaping the inlet edges of the exhaust hood. This increases the range of contaminant capture, reduces noise, and prevents contaminants from escaping from the exhaust hood by eliminating the vortex zones and reducing the fan power. •Two designs of shaped exhaust hoods have been set up.•Local drag coefficients have been determined experimentally for exhaust hoods.•Numerical computations are compared with experimental measurements.•We show that shaping increases the capture range of an exhaust hood.•Shaped exhaust hoods reduce fan power consumption.