Flow Coefficient Specific Speed

This represents the linear effect of tip speed and the square of impeller size on the flow of a specific impeller. Referring to Figure 12-46, very low flow coefficients for a specific type of centrifugal or axial flow machine cause excessive wall friction or leakage losses, and very high-flow coefficients tend to he subject to turbulence losses due to insufficient flow guiding. ... 

P[3 = P[ = fan input power D = fan size (impeller or wheel diameter) N = fan speed Nj = fan specific speed p = fan air density Q = fan flow rate Kp = compressibility coefficient L, = sound power level Pjt = fan total pressure Pjy = fan velocity pressure Pj-s = fan static pressure... 

Specific speed—A ratio obtained by manipulating the ratio of the flow coefficient to the head coefficient of a pump. Values obtained are values applying at the best operating efficiency. 

A slurry pump is to be designed for a head at best efficiency of 150 ft at a flow rate of 1200 gpm. Assuming a head coefficient of 0.5 (by U.S. definition), determine the diameter and the speed of rotation if the specific speed is 1100 (in U.S. units). 

Chemicals may be removed from some aquatic environments by volatilization. The intrinsic potential for volatilization is determined by the Henry s Law constant (H) of the substance. Volatilization from the aquatic environment is highly dependent on the environmental conditions of the specific water body in question, such as the water depth, the gas exchange coefficients (depending on wind speed and water flow) and stratification of the water body. Because volatilization only represents removal of a chemical from water phase, the Henry s Law constant caimot be used for assessment of degradation in relation to aquatic hazard classification of substances. Substances that are gases at ambient temperature may however for example be considered further in this regard (see also Pedersen et al, 1995). 

A Bingham slurry with a concentration of 50% by weight is tested in a plastic-lined pipe with an inner diameter of 2.5 in. The tests indicate a yield stress of 1.5 Pa, a slurry mixture specific gravity of 1.54, and a coefficient of rigidity of 0.4 Pa s. Assuming a flow speed of 4 ft/s in a laminar regime, determine the friction factor by Buckingham s equation. 

The air speed in the main part of the flow is distributed more or less uniformly. On passing around adhering particles lying in the boundary layer, the speed of the flow changes from a specific value to zero. The change in the velocity and the indeterminacy of the coefficient c [Cx = / (Re) ... 

A positive reactivity ( 0.1) is inserted stepwise by withdrawing the CRs. The feedwater pump speed and the turbine control valve stroke are kept constant. The results are shown in Fig. 7.68 [31]. The reactor power increases about 10% almost stepwise due to the prompt jump and then gradually decreases due to the reactivity feedbacks from the fuel temperature and coolant density. This behavior implies that the Super FR also has inherent self controllability of the reactor power despite the much smaller density reactivity coefficient compared to that of the Super LWR. The main steam temperature increases, which leads to an increase in the main steam and core pressures because the specific volume of the main steam increases. The increase in the core pressure leads to a decrease in the feedwater and core flow rates, which increases the main steam temperature further. As a result, the maximum increase in the main steam temperature is nearly 40°C while that in the Super LWR is only 9°C (see Fig. 4.10). 

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