The port design using CAD is based on AVL’ s data base to ensure that the required charge motion is generated by the ports. As described before at part load (only charge motion port is open) a high level of charge motion shall be generated (picture 'Part Load Operation'). At higher loads (both ports open) only little charge motion is required (picture 'Full Load Operation').
To ensure this two different ports - a charge motion port and a filling port are used.
The flow coefficient and swirl number when only the charge motion port is open and with both ports open are measured and optimised on the flow test bed using a core box which is manufactured by rapid prototyping and equipped with valve guides, valves and seat rings.
When both ports are open only very little charge motion is generated.
With closed quiescent port (filling port) a high mean swirl number is achieved.
<< Previous Page
Next Page >>