Solid-Fuel Rocket Motor Efficiency Improvement Scheme - Novel Combustion Concepts for Sustainable Energy Development - page 528

(ii): Two-phase water outlet flow

Flow direction

(iii) : Liquid exit flow

(i): Liquid inlet flow

Fig. 2 Liquid water mass conservation illustration

V w,i

V w,e

h w,i

h w,e

Fig. 3 Water level and velocity at inlet and exit

conservation in Eq. ( 7 ) must be employed. Figure 2 illustrates the mass conser-
vation region in control volume for each term in Eq. ( 8 ).

Q m ; w ; i ¼ Q m ; w ; b þ Q m ; w ; e

ð 8 Þ

ð i Þ ð ii Þ ð iii Þ

where Q denotes volumetric fl flow rate, and the term (i) is measured directly from the

fl flow meter as displayed in Fig. 3 . The term (iii) is the volumetric fl flow rate of

the sum of the dispersed liquid water particles in the two-phase fl flow exiting the

channel. The term (iii) is the volumetric flow rate exiting the channel and is

approximated by calculating the mean water exit velocity and boundary height. The
extent of dispersed liquid water is a good indicator of breakup; however, it is not
easy to measure dispersed liquid water or Q m,w,b directly; therefore the measure-
ment needs to be carried out by subtracting measured value of liquid inlet

fl

fl ow by

exit fl flow. The volumetric fl flow rate of inlet and exit are de ned in Eqs. ( 9 ) and ( 10 ).

Q m ; w ; i ¼ h w ; i v w ; i Y ð 9 Þ

Q m ; w ; e ¼ h w ; e v w ; e Y ð 10 Þ

where h w,i , h w,e ,v w,i , and v w,e are water level of channel and water velocity of inlet
and exit, respectively. The Y in Eqs. ( 9 ) and ( 10 ) is the width of the fl flow channel.

The illustration of the mass flow component in both equations is shown in Figure 3 .

Since Q m,w,i and Q m,w,e are known, Q m,w,b can be calculated which permits the
introduction of the breakup ratio B as expressed as:

fl