Question

For the design of non-scouring channels in coarse alluviums, the shield’s entrainment function should be ____________

(a) Fs > 0.056

(b) Fs < 0.056

(c) Fs = 0.056

(d) Fs = 0

The question was posed to me by my college director while I was bunking the class.

The query is from Irrigation Channels Design in section Sediment Transport and Irrigation Channels Design of Irrigation Engineering

Answer 1

The correct option is (c) Fs = 0.056

The explanation is: According to Shield for coarse alluvium, Fs = 0.056 (d > 6 mm). When the particle Reynold’s number is more than 400, the application of the curve plotted by Shield between Reynold’s number and entrainment function becomes simpler. Also, the value of the entrainment function becomes constant and equal to 0.056.