Abstract:
A vortex shedding model is developed to predict the flow fields
around turbine flowmeter blades. This model is used to simulate the
flow separation and reattachment in the leading edge areas and the
wake flows of the blades. Lewis's inverse blade design method is
developed and quite successfully applied to simulate the displacement
effect of the separation bubbles in the leading edge areas.
A new method is introduced to apply the Kutta condition in
unsteady flows around the blades wi th separation points on a blade
surface or the flow with blade interaction. This method does not
require a large amount of iterative calculation.
A model is built up to predict the turbine flowmeter performance
when the inlet flow conditions are known. The panel method is applied
to predict the inlet flow conditions for the cases without inlet
swirl.
An experimental study of the flow inside a turbine flowmeter is
carried out using Laser Doppler Anemometry(LDA) to measure the
throughout velocity fields around a flowmeter at different flowrates
and with different inlet swirls. A clear picture of the flow field is
thus obtained. The measured resul ts are also used to validate the
developed turbine flowmeter performance prediction model.
The numerical prediction are tested with experimental results. The
theoretical and experimental data agree with each other very well in
the cases without inlet swirl and reasonably ",ell in other tested
cases with inlet swirl.
