Continuity Equation

Fluid Flow CONTINUITY EQUATION Example: Continuity Equation - Centrifugal Pump The inlet diameter of the reactor coolant pump shown in Figure 3 is 28 in. while the outlet flow through the pump is 9200 lbm/sec. The density of the water is 49 lbm/ft³. What is the velocity at the pump inlet? Solution: A_inlet pr 2 (3.14)^� � � � � � 14 in^� � � � � � 1 ft 12 in 2 4.28 ft² m_inlet m_outlet ₉₂₀₀lbm sec (rAv)_inlet 9200^lbm sec v_inlet 9200^lbm sec Ar 9200^lbm sec (4.28 ft²)^� � � � � � 49^lbm ft³ v_inlet 43.9 ft sec The above example indicates that the flow rate into the system is the same as that out of the system. The same concept is true even though more than one flow path may enter or leave the system at the same time. The mass balance is simply adjusted to state that the sum of all flows entering the system is equal to the sum of all the flows leaving the system if steady-state conditions exist. An example of this physical case is included in the following example. Rev. 0 Page 13 HT-03