Jean-Baptiste Bélanger: hydraulic engineer and academic

Jean-Baptiste Bélanger (1790–1874) worked as a hydraulic engineer at the beginning of his career. He developed the backwater equation to calculate the freesurface profile of gradually varied, steady open channel flow. He also introduced the concept of critical flow and the numerical technique called the direct step method. Later, as an academic staff member at the leading French engineering schools (Ecole Centrale des Arts et Manufactures, Ecole des Ponts et Chaussées and Ecole Polytechnique), he developed a new university curriculum in mechanics and wrote several textbooks including a seminal text in hydraulic engineering. His influence on his contemporaries was considerable, and his name is written on the border of one of the four façades of the Eiffel Tower. Bélanger’s leading role demonstrated the dynamism of practising engineers at the time, and his contributions paved the way to many significant works in hydraulics and fluid dynamics during the late nineteenth and early twentieth centuries.