Variable geometry fluid flowmeter
US4136565A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 1978 |
| Grant date | Jan 30, 1979 |
| Priority date | — |
| Expiry date | Apr 20, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/44
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A low pressure drop air flowmeter for an automotive engine is disclosed. The meter includes a main air flow passage, a relatively small venturi to receive a portion of the air flow, a pressure port for sensing stagnation pressure in the main passage, a pressure port for sensing static pressure in the throat of the venturi, and a set of swirl vanes disposed adjacent the outlet of the venturi and operative to impart a swirl to the remainder of the air in the main passage, thereby creating a reduced pressure at the venturi outlet for amplifying the pressure difference between the stagnation and static pressure without appreciably increasing the pressure drop across the flowmeter. A geometrically reconfigurable element is included in the main passage resulting in a swirl rate which increases with increasing air flow but at a decreasing rate. This characteristic results in an output pressure differential signal which varies substantially linearly with flow rate over a relatively large range of operation. The reconfigurable element can be of the iris type which varies the effective tip radius of the swirl vanes, or alternatively, can comprise flexible swirl vanes which present a variable…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.