Canadian engineer . ons.—Hydraulic principles properlyapplied bring the design of a water wheel within the fullgrasp of the engineer. Hydraulic formulas contain manyconstants and coefficients, and it has taken time, patienceand experience to gain a correct knowledge of the propervalues of these. But once having gained a knowledge ofthem for various types of nozzles and surfaces, a fullknowledge of velocity relations and correct design can bearrived at. in general, the calculations necessary in designing awater wheel runner will be left to the manufacturer and willnot be taken up here, but we w
Canadian engineer . ons.—Hydraulic principles properlyapplied bring the design of a water wheel within the fullgrasp of the engineer. Hydraulic formulas contain manyconstants and coefficients, and it has taken time, patienceand experience to gain a correct knowledge of the propervalues of these. But once having gained a knowledge ofthem for various types of nozzles and surfaces, a fullknowledge of velocity relations and correct design can bearrived at. in general, the calculations necessary in designing awater wheel runner will be left to the manufacturer and willnot be taken up here, but we will discuss briefly the mannerin which the speed of a turbine runner is affected by theangles of the buckets and guides, as we will use this later. Reference may now be made to the sectional drawingsFigs. I, 2 and 3, and the corresponding runners, Figs. 4, 5and 6. These sketches show the general designs of theguides and runners for three types and angular relations ofsame. The diameter is the same for each Fig. 1. (See Fig. 4 for Runner.) See Fig. 5 for Runner.) Let A equal the angle between the tangent of the peri-phery of the runner and the direction of the flow of thewater as it leaves the guides. Let B equal the angle between the tangent to the peri-phery of the runner and the entering edge of the runnerbucket. Let V equal peripheral velocity of the runner in feet persecond. Let H equal effective head in feet. Led D equal diameter of runner in V = 52 VH \/: sin (A + B) (approximately) sin B cos A60 V rev. per mm. = D A consideration of these two formulas clearly indicatesthat the diameter of the runner and the rev. per min. de-pend upon the angles chosen. Therefore, with a givendiameter, to obtain rev. per min. angles must be chosen tosuit and the design of the bucket made to correspond. It is convenient to use in the process of design a headof one foot as a basis for calculations. Having made cal-culations for unity head, values for other heads ar
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishertoron, bookyear1893
