An identity derived by a 90° turn of a classical fluid-mechanics problem
We take the classical problem of laminar flow in a rectangular duct and turn the duct 90°. Driven by the same pressure gradient, the volume flow rate should remain the same. This leads to an identity that relates a polynomial to infinite series of tanh functions. We discuss the mathematical properties of this identity and verify it by two different methods.
Publication Source (Journal or Book title)
Applied Mathematics E-Notes
Wong, H. (2020). An identity derived by a 90° turn of a classical fluid-mechanics problem. Applied Mathematics E-Notes Retrieved from https://repository.lsu.edu/mechanical_engineering_pubs/427