Abstract: Numerical
simulation is applied to design the internal flow passage of a fluidic
flowmeter and research on the velocity distribution and pressure
distribution of the flow field in the fluidic flowmeter, as well as the
mechanism of fluid alternation and oscillation induced by the Coanda
effect. The results of the simulation indicate that the deflection of
main jet is always accompanied with strength alternation of two vortexes
acting on the main jet together. Subsequently a fluidic flowmeter
prototypeis optimized based on the simulation model. Experimental study
is carried out to verify the effects of fluidic vibration and the
characteristic relationship between conduit velocity and vibration
frequency. A fluidic flow sensor with a measuring range from 0.55 m/s to
6.5 m/s for gas medium and an accuracy grade higher than grade 2 is
finally developed. Hence effective methods of structural improvement and
optimum design for fluidic flowmeter are provided.
Key words: Fluidic
flowmeter Coanda effect Fluid vibration
Flow field simulation
CLC No: TP69
国家自然科学基金资助项目(50175097),Received
20050721, received in revised form 20060118 |