Calibration of the NASA GRC 16″ Mass-Flow Plug

The results of an experimental calibration of the NASA Glenn Research Center 16″ Mass-Flow Plug (MFP) are presented and compared to a previously obtained calibration of a 15″ Mass-Flow Plug. An ASME low-beta, long-radius nozzle was used as the calibration reference. The discharge coefficient for the ASME nozzle was obtained by numerically simulating the flow through the nozzle from the WIND-US code. The results showed agreement between the 15″ and 16″ MFPs for area ratios (MFP to pipe area ratio) greater than 0.6 but deviate at area ratios below this value for reasons that are not fully understood. A general uncertainty analysis was also performed and indicates that large uncertainties in the calibration are present for low MFP area ratios.