Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.
This paper deals with the experimental analysis and
numerical simulation regarding the flow forces of a
mechatronical pressure regulator for natural gas powered
internal combustion engines.
For the experimental analysis a measurement device was
constructed to determine these forces as well as other global
flow parameters by variation of the pressure ratio and the
strokes of the valve gate.
The series of tests were simulated on the basis of the
Computational Fluid Dynamics (CFD)-code FLUENT. Thereby
the model was validated through the comparison of the results
deriving from the experimental analysis and the results
provided by the numerical simulation. It was shown that the
flow forces have a strong dependence on the pressure ratio but
are not influenced by the mass flow rate. Accordingly the flow
forces are independent of the stroke.
By the use of the numerical simulation a visualization of the
inner flow characteristics was obtained. Thus the potential for
an improvement in the geometry was derived. Besides a
generation of eddies in the low and high pressure chamber,
backflow occurred in the valve bung as a result of shocks. This
took place at low pressure ratios and resulted in a decreasing
flow coefficient due to contraction and deceleration of the fluid
entering the control edge. At high pressure ratios, a relocation
of the flow contraction towards the theoretical flow cross
sectional area and a decreasing of the generation and impact of
eddies in the valve bung were detected.