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Blade efficiency

Substituting into equation (15.32) gives the blade efficiency as... [Pg.177]

It is important to emphasize the limitations on the use of this equation. It is essentially a design equation and it represents the variation in blade efficiency with blade/gas speed ratio for a turbine impulse blade under the following conditions ... [Pg.177]

For example, if the nozzle angle is 20°, the inlet and outlet blade angles will each be 36°, and the optimum speed ratio will be 0.47, giving a blade efficiency of 0.883. [Pg.178]

Off-design conditions in an impuise stage blade efficiency and stage outlet velocity in the absence of blade and nozzle inlet loss... [Pg.178]

Blade efficiency is again the change in momentum in the direction of wheel motion divided by the available kinetic energy, as in equation (15.32). We shall call the value from this first step, where the gas is assumed to enter the blade with no loss, rfBa- Substituting from... [Pg.178]

This fraction of the kinetic eneigy possessed by the mid-stage gas stream will be converted into additional enthalpy. There is no mechanism for reconverting this enthalpy into kinetic energy in an impulse blade, so there will be no recovery of any energy lost at the blade entry in an impulse stage. A reasonable estimate may be 1. The loss correction factor to be applied to the initial value of blade efficiency is simply (l-X ). The final calculation of blade efficiency for an operating impulse blade is thus... [Pg.180]

Thus the blade-to-gas speed ratio at which the blade will abstract no useful work is Rb = 1.41 when ai = 20°. This is indicated in Figure 15.6 by the blade efficiency falling to zero at this point. [Pg.181]

The shock correction factor (1 — A. ) remains close to unity at low speed ratios, but falls at high-speed ratios, where it causes a significant difference to arise between the uncorrected blade efficiency, t Ba, and the blade efficiency corrected for inlet shock losses, tib. [Pg.181]

Simulation of Industrial Processes for Control Engineers Blade efficiency... [Pg.182]

Figure 1S.S Blade efficiency for an operating impulee blade with nozzle angle = 20°. Figure 1S.S Blade efficiency for an operating impulee blade with nozzle angle = 20°.
Blade efficiency at design conditions for a 50% reaction stage... [Pg.183]

We may find the maximum blade efficiency for a given nozzle angle, ai, by differentiating with respect to speed ratio, Rb, and setting the result to zero. (We will assume that the nozzle efficiency over the moving blades is unaffected by changes in speed ratio, Rb-) This yields the optimal speed ratio as... [Pg.184]

The specific work, w, for an impulse stage may be written in terms of the blade efficiency, ijb, using equations (15.31) and (15.32) ... [Pg.191]

We may evaluate the nozzle efficiency and the blade efficiency using the methods described in Chapters 14 and IS, and so it is possible to calculate the stage efficiency using equations (16.17) and (16.24). [Pg.192]

If for a usual rotoklon efficiency of trapping of a dust was small and sharp depended from fluid level, filled in the apparatus in the presence of impeller blades efficiency trapping in all velocity band of air was high and did not depend on liquid level in the apparatus (See Figures 12.4-12.6). [Pg.200]

See other pages where Blade efficiency is mentioned: [Pg.364]    [Pg.364]    [Pg.3]    [Pg.178]    [Pg.181]    [Pg.184]    [Pg.185]    [Pg.185]    [Pg.186]    [Pg.190]    [Pg.192]    [Pg.410]    [Pg.413]    [Pg.414]    [Pg.364]    [Pg.204]   


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Blade

Blade efficiency at design conditions for a 50 reaction stage

Blade efficiency at off-design conditions for a 50 reaction stage

Bladed

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