13-25. In The Effect of Nozzle Design on the Stability and Performance of Turbulent

Chapter 13, Problem 13-25

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13-25. In The Effect of Nozzle Design on the Stability and Performance of Turbulent Water Jets (Fire Safety Journal, Vol. 4, August 1981), C. Theobald describes an experiment in which a shape measurement was determined for several different nozzle types at different levels of jet efflux velocity. Interest in this experiment focuses primarily on nozzle type, and velocity is a nuisance factor. The data are as follows: Nozzle Jet Efflux Velocity (m/s) Type 11.73 14.37 16.59 20.43 23.46 28.74 1 0.78 0.80 0.81 0.75 0.77 0.78 2 0.85 0.85 0.92 0.86 0.81 0.83 3 0.93 0.92 0.95 0.89 0.89 0.83 4 1.14 0.97 0.98 0.88 0.86 0.83 5 0.97 0.86 0.78 0.76 0.76 0.75 (a) Does nozzle type affect shape measurement? Compare the nozzles with box plots and the analysis of variance. (b) Use Fishers LSD method to determine specific differences between the nozzles. Does a graph of the average (or standard deviation) of the shape measurements versus nozzle type assist with the conclusions? (c) Analyze the residuals from this experiment.