Method for establishing noise source model of engine fan in pipeline

The invention relates to a method for establishing a noise source model of an engine fan in a pipeline, which comprises the following steps of: extracting a theoretical basis from measured data: sound propagation of the engine fan in the pipeline is represented by a solution of a sound propagation control equation which can be summed through a mode in a propagation mode form, in a cylindrical coordinate system, the control equation is effective in a flow channel, and in the cylindrical coordinate system, the control equation is effective in the flow channel; solving is carried out according to the boundary condition on the flow channel wall, and for the rigid wall surface, the boundary condition only disappears of the normal speed on the wall surface; on the theoretical basis, a control equation and a boundary condition are converted into a linear problem, and a solution of any source distribution in a flow channel in a pipeline is given through convolution between a Green function and a source function; and