Granulometric technique by photographic methods ofYjet nozzles under back pressure condition

As its hard to achieve useful data by optical measurement granulometric technique of Yjet nozzle in back pressure condition, a photographic method depending on morphology was put forward to get detailed data of the Sauter mean diameter (SMD). The error among photographic methods and phase Doppler particle analyzer (PDPA) was less than 12%. The experimental results indicated that SMD decreased with air flow rate of 0g/s and increased with air flow rate of 55g/s along with pressure rising and flow rate growing under back pressure condition. SMD almost stayed the same by different flow rates under the same pressure condition with air joining. Finally through tests by simulating real variablecondition process in combustion chamber, it was concluded that SMD under variable pressure condition was almost the same with little air joining in nozzle.