Purpose - The purpose of this paper is to theoretically investigate the thermal and hydrodynamic performance of the flow pattern of fluid in the charged jet. The flow pattern includes laminar flow in which all fluid layers move at different accelerated speeds, and shear forces between the fluid layers give rise to friction forces. This is a favorable condition for the parallel arrangement of the branches on polymer molecules. Design/methodology/approach - The dynamic mechanism of the flow pattern is conducted through analyzing the forces acting on the charged jet. The differential equation obtained in the analyzing process has the solution designating the laminar flow pattern of the fluid in the charged jet. Findings - The fluid in the charged jet flows in laminar pattern, which is favorable to the parallel arrangement of the branches on polymer molecules. Research limitations/implications - Although the flow pattern is conveyed by means of the simple condition of uniformly accelerated motion, it has the similar effect on the arrangement of the polymer molecules in general conditions, such as non-Newtonian fluids and non-uniformly accelerated motions. Originality/value - The laminar flow introduced by this paper to the charged jet implies anisotropic properties of the electrospun nanofibers.