Department of Civil Engineering, Indian Institute of Technology, Kharagpur.
The main aim of this article is to bring out the need for further studies in open channels to acquire a knowledge of the pattern of variations of Manning’s Coefficient of roughness n with stage of flow with particular reference to closed conduits. This will have wide applications particularly in design of tunnels. The development of Manning’’s formula, the existing methods to guide a proper choice of the value of n and application of Manning’s relation with special reference to conduits with gradually closing top have been dealt with in the following pages. A list of important references on the subject has beenfurnished at the end.
