| 摘要 |
The effective flow area of a restriction in a gas flow passage, such as that of a gas turbine nozzle or vane, is determined by use of a large reservoir containing pressurised gas which is discharged through the passage in a blowdown operation in which the ratio of back pressure of the restriction to gas pressure in the reservoir is maintained below critical for sonic flow. Timer means may be used to measure the time for a predetermined fall of pressure in the reservoir whilst there is sonic flow through the restriction. |
