Numerical Simulation for Prediction of Wetness Content in Wet Steam for Convergent - Divergent Nozzle

Abstract

This research is to find a wetness using the (laser beam) optical Forward Scattering Method (F.S.M.) which is applicable to calculate the wetness in a convergent-divergent De-Laval steam nozzle operating (1.3 Mach number) which may be works at wet steam with pressure (1) bar and temperature (373) K .The light source of He-Ne laser of wave light (λ=0.632) µm was used to prediction the wetness in nozzle a wet steam flow. Both droplet diameter of water (Dr) and relation of intensity of light S= ln⁡(I_B/ Iₒ) are assumed to be (Dr=10,30,50,70,100 µm) and (S = 0.9,.0.8,0.7,0.6,0.5 ) respectively. From the relation of light intensity pattern of many diameter droplet of water (Dr) and different droplet size distribution N (Dr), the MATLAB program can calculate the light attenuation coefficient (Ks) consequently. The increase of the droplet size distribution, N (Dr), leads to decrease the values of (S) and (Ks). The increase of the droplet diameter causes increase of the scattered light, and the minimum value of scattering light is with (Dr= 10µm) for the tested samples. The wetness of steam (yₒ) = (1,3,557,10) % ,which depend on the [Dr, N(Dr)] in the scattered zone(Vt), can be determined easily by the MATLAB program. The radius of droplet water in two – phase can be adversely calculated by using the research output that then the concentrations or wetness is previously specified.