Velocity diagrams impulse diagram

Impulse diagram. For the impulse rotor, the reaction is zero, so the relative velocity of the gas is constant, or = W/. If the work factor is less than 2.0, the exit swirl is positive, which reduces the stage work. For this reason, an impulse diagram should be used only if the work factor is 2.0 or... 

The pressure/impulse diagrams in Fig. 10.8 illustrate the respective changes recorded for a detonation (line 1), a constant volume explosion (line 2) and a deflagration with 200 m/s velocity (line 3) and 150 m/s (line 4). Accounting for the finite duration of the blast wave is of crucial importance because of the potential reduction of dangerous distances. 

Gibson method. The mean velocity in a penstock leading from a reservoir can be determined by rapidly closing a valve at the lower end and recording a pressure-time diagram at a point just upstream from the valve. The principle that impulse equals change of momentum can be applied to the mass of liquid between the reservoir and the point of measurement. The impulse is given by the area under the recorded pressuretime curve, and from this the initial velocity can be determined [10]. 

Figurg 15.2 Diagram of impulse stage showing velocities.

Fig. 10.8 Diagram of blast wave pressure/impulse resulting from H2 + air cloud explosion ( H2 - 100 kg) for various combustion modes line 1 - detonation line 2 - constant volume explosion line 3 — deflagration with 200 m/s velocity line 4 - deflagration with 100 m/s velocity 5 - boundary of deflagration regimes...

---