Translating Equations Into Their Physical Meaning as an Effective Tool of Engineering

This paper is an extension of the discussion pertaining the need for, and the benefits of the capability to translate a mathematical expression into a description of a relevant physical event, respectively of a physical situation. It shows, how such a translation has made it possible to recognize the shortcomings of the deeply-rooted conception, that the outlet angle of the impeller blades is the most significant design parameter of a rotodynamic pump. The awareness of these shortcomings, in turn, has led already to the development of a more reliable approach for calculating the heads generated by a rotodynamic impeller, (Compare Fig. 2.). It has also made possible to solve to a number of additional problems which, in the past, could be solved only by the costly and time consuming method of trial and error. This paper also discusses the physical meaning of the Navier-Stokes equations. It shows how the translation of these equations into their physical meaning made it possible to explain several seemingly enigmatic results of tests. In addition to the above, this paper also discusses a number of problems which need yet to be explored in the future, in order to be able to turn CFD into a useful tool for the design of rotodynamic pumps.