Tunnel Calibration Research Articles

A critical examination of the turbulence instrument used in the Marsta micro-meteorological field project

A turbulence instrument described earlier (Hogstrom, 1967), and used in an extensive micro-meteorological field project, has been examined critically. Static wind tunnel calibrations give accurate, reproducible results. Field measurements and theoretical considerations indicate complications in the dynamical situation, however. It is shown that the instrument is well suited for the measurement of the horizontal component of the wind and its rapid fluctuations. For the measurement of the turbulent fluxes of sensible heat and of water vapour a correction of order of magnitude 10% must be applied. The instrument is further shown to be unsuited for measuring the shearing stress and the variance of the vertical velocity component DOI: 10.1111/j.2153-3490.1974.tb01646.x

A method for checking the consistency of velocity computations from hot wire anemometer measurements in variable density flows

A method is presented for checking the consistency of air velocity calculation from hot wire anemometer measurements in an air flow which undergoes a continuous variation of density with time. The method gives a means of checking correction factors applied to ambient wind tunnel calibration tests to allow for variable density conditions. A particular application of the method to air velocity measurement in a motored internal combustion engine is discussed.

A mechanical wind speed and direction seven day recorder

A relatively inexpensive mechanical recorder developed to provide seven days simultaneous and continuous record of wind speed and direction on the same time base of a 10 1 4 -inch circular chart is described. The validity of the data provided by the instrument has been confirmed by wind tunnel calibrations and field tests using standard electronic instruments. The instrument can be a useful tool for the acquisition of wind data, especially where shortages of manpower, electricity or funds are limiting factors in the pursuit of the program.