Contents preface (VII) introduction 1—37

4.8.3.3. Open Area of Well-Screen
For head loss through the well screen to be minimum, Peterson et al. (18) have suggested that the value of the parameter C_c A_p L/D should be greater than 0.53. Here, C_c is the coefficient of contraction for the openings, A _p the ratio of the open area to the total surface area of the screen, L the screen length, and D is the diameter of well screen. Theoretical studies conducted at the UP Irrigation Research Institute have shown that the parameter C_c C_v A_p L/D should be greater than 1.77. Here, C_v is the coefficient of velocity. A factor of safety of 2.5 is further recommended by Sharma and Chawla (16). This means that C_c C_v A_p L/D should be greater than 4.42.