Laserfiche WebLink
<br />\ <br />--4~ <br />L <br />-~~l, <br />----" <br /> <br />'> <br />, <br /> <br />tion, M = Wig where W is weight and g is the acceleration of gravity. <br />During the isolated time period under consideration, W is the product <br />of flow velocity times cross sectional area of the streamtube times the <br />time interval. The resulting kinetic energy is W . V212g. <br />The other energy components are the internal energy, I . W, which <br />is associated with the molecular forces in the fluid (where I is in- <br />ternal energy per unit weight); and the potential energy, Y . W, where <br />o <br />Y is height of the streamtube in feet or meters above a specified <br />o <br />da tum. <br /> <br />" <br /> <br />'. <br />'. <br /> <br />" <br /> <br />'. <br /> <br />The principle of conservation of energy requires tnat total energy <br />at every point in space be referenced vertically above the same datum. <br />Looking then at the two points of interest, the kinetic energy, internal <br />energy and potential energy combine to form the total energy as sho~m <br />in the following equations: <br /> <br />El <br /> <br />2 <br />= W' Vl/2g + 11 . W + YOl . \'1 <br /> <br />(2-2) <br /> <br />and <br /> <br />E2 · W. V~/2g + 12 . W + Yo . W <br />2 <br />where all terms are as previously defined. <br /> <br />(2-3) <br /> <br />The net work exerted between points 1 and 2 (WORK in equation 2.1) <br />can be calculated from the following equation: <br /> <br />WORK = F2dl- Fldl <br /> <br />(2-4) <br /> <br />where: <br />F = force in pounds (lbs) or kilograms (kgf) <br />dl = the length of the streamtube between points <br /> <br />1 and 2 <br /> <br />2.03 <br />