Hunter Rouse—His Work in Retrospect

Abstract

In 1906, the year Hunter Rouse was born, hydraulic engineering was on a far slower development path than was structural engineering, the other major branch of civil engineering. The introduction of statics and solid-mechanics theories into engineering practice during the previous 2 centuries had greatly hastened the rationalization of structural engineering, while hydraulic engineering remained largely a practice of rote rules and hindsight empiricism. Hydraulic engineers of the 1700s and the 1800s had, to some extent, tried to apply basic fluid mechanics principles to the design of hydraulic structures, but had found the fluid mechanics as formulated by mathematicians like Daniel Bernoulli, Leonhard Euler, Jean D’Alembert, and Issac Newton to be of little practical use. Hydraulic engineering practice and fluidmechanic theories seemed disconnected. In 1906, however, fluid mechanics and hydraulic engineering were entering an era of momentous development. Emblematic of this development was the 10-min presentation by Ludwig Prandtl of Germany during the 3rd International Congress of Mathematicians, in 1904. Prandtl illuminated the consequences of two related concepts that profoundly influence fluid mechanics: the no-slip condition for fluids at rigid boundaries, and boundary layer formation for viscosity-affected flows over solid boundaries Prandtl 1905 . These physical conditions must be satisfied to properly analyze the motion of fluids with small but still appreciable viscosity, like water. Their importance had been partially recognized earlier e.g., Froude 1872 , but Prandtl’s explanations and illustrations, supported by other emerging concepts in turbulent flow and the rising use of laboratories, provided new insights clearing the path for hydraulic engineering to develop rapidly. Hunter Rouse 1906–1996 contributed significantly to these developments. Early in his career, Rouse recognized that he stood at an exciting historical conjunction of scientific concepts and engineering. Reports, papers, and photographs of Rouse and fellow young hydraulicians during the early 1900s convey a palpable sense of excitement and mission Fig. 1 . Hunter Rouse became widely admired as the researcher and educator who best championed the application of fluid mechanics theory, validated by contemporary experimentation methods, to water flow processes in hydraulic engineering. This application, commonly called hydraulics, elevated hydraulic engineering to a substantially more rational plane than it had previously occupied. Although he received numerous recognitions and awards for his work, and its impact carries on, knowledge about the full extent of his work has faded. Today he is most remembered for his books on the history of hydraulics, his lucidly written textbooks on fluid mechanics and hydraulics, and his leadership of a promi-