عنوان مقاله [English]
In hydraulic, velocity distribution as a key parameter for determining the flow profile, such as flow, shear stress distribution, sedimentation, erosion, loss of head, the coefficient of energy and momentum coefficient is needed, so the calculation of flow velocity is an important part of sewers design. The flow in a sewer, regardless of its geometry, is three-dimensional turbulent free surface flow. The introducing of the entropy based on probability in hydraulic by Chiu gives the possibility to develop a simple equation to evaluate the velocity and the discharge in the cross section. The method was applied to a study of velocity field of flow in narrow compound sewer. The primary flow distribution was investigated under various hydraulic conditions. The validation of the method and velocity distribution and discharge was carried out by comparing the estimated results with the measured findings at the field sites. Analysis of velocity distribution based on the probability concept has made it possible to determine the cross-sectional primary velocity distribution and discharge without having to deal with the geometrical shape of cross sections, which tend to be extremely complex in real sewers.