Abstract
Being one of the cheapest devices for air flow measurement within a wide range of flowrates, Venturi-type air flowmeters (VTAFs) can also be used for measuring very small air flowrates, usually less than 50 to 100 liters per minute, which is usually encountered in lab-scale applications. This study presents a model-based evaluation of VTAFs for lab-scale applications. The pressure and velocity fields in mini VTAFs were calculated by computational fluid dynamics (CFD) model using Ansys Fluent™. Results showed that sensitive and accurate measurements of volumetric flowrate can be achieved using mini VTAFs. A diameter ratio of 0.6 for the venturi throat provides a minimum detection limit of 2.46 LPM while an overall pressure drop of around 115 Pa at an air flowrate of 50 LPM at 20°C.