online_scour_froehlich1988:  Calculation of pier scour using the Froehlich (1988) formula    Formula: Fr1 = v1 / (g y1)1/2 ys = 0.32 b φ Fr10.2 (be / b)0.62 (y1 / b)0.46 (b / D50)0.08 + b [ SI units (metric):  ys, y1, and b in m; v1 in m/s; D50 in mm ] [ U.S. Customary units:  ys, y1, and b in ft; v1 in ft/s; D50 in mm ] [ Fr = Froude number; g = gravitational acceleration ] Reference INPUT DATA:      [Description]     [Sample Input] Select:       SI units (metric) U.S. Customary units Flow depth y1 :         Flow velocity v1 :         Pier width b :         Angle of attack θ of the flow (degrees):         Median diameter of bed material D50 :         Pier nose shape:       Square nose Round nose Sharp nose OUTPUT: System of units:  SI units (metric) Pier nose shape:  Square nose ♦  Scour depth ys :      Press button to or recalculate   Your request was processed at  04:53:45 pm on September 19th, 2018   [ 180919  16:53:45 ]. Thank you for running   online_scour_froehlich(1988)   Please call again.   [171023]