Position energy
Fig.A-21 presents an analysis of positional energy change in a general element
of a pipeline system. We treat this element as a black box: its inertnal
constrction is not studied and we just assume that somehow,
when passing through this element,
fluid acts upon some device and
performs work. Let us that, all other components of fluid energy
remaining constant, this work is performed only at the price of
decreasing position energy. Note that to make possible such change,
the vertical position
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Fig.A-21 Derivation of the expression for position energy |
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Fig.A-22 |
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Johann Bernoulli | Daniel Bernoulli |
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Born: 8 Feb 1700 in Groningen, Netherlands Died: 17 March 1782 in Basel, Switzerland -------------------------------------------- Daniel Bernoulli's most important work considered the basic properties of fluid flow, pressure, density and velocity, and gave their fundamental relationship He was the second son of Johann Bernoulli and brother of Nicolaus(II) Bernoulli and Johann(II) Bernoulli. In 1725 Daniel and his brother Nicolaus were invited to work at the St. Petersburg Academy of Sciences. There he collaborated with Euler, who came to St. Petersburg in 1727. In 1731 Daniel extended his researches to cover problems of life insurance and health statistics "Specimen theoriae novae de mensura sortis". In 1733 Daniel returned to Basel where he taught anatomy, botany, physiology and physics. His most important work was "Hydrodynamica"" which considered the basic properties of fluid flow. In this book he also gave a theoretical explanation of the pressure on the walls of a container. He also established the basis for the kinetic theory of gases. |
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Vaclav TESAR : "BASIC FLUID MECHANICS"