Numerical simulation of saturated fuel preparation for fuel icing tests
In order to study the influence rules of water content in saturated fuel for fuel icing tests,and find the way to meet airworthiness requirement on fuel-water homogeneity,numerical simulation of water injection and circulation system was proposed.Euler-Lagrange algorithm represented continuous and discrete terms respectively,and discrete phase model(DPM)simulated the collision,fusion and fragmentation of water particles.Water droplet spray and water-fuel two-phase flow cycle was simulated,to examine effects of injection position,pressure of the pump outlet and in/out arrangement of fluid on the water content in the fuel.Based on statistical sampling on the mass concentration of the discrete terms for different regions in the cycle system,water-fuel mixing within the prescribed time by the airworthiness standard was analyzed.Water injection experiment for the fuel cycle was conducted by using water distribution apparatus,and the water content in the cycle fuel without passing through the fuel-water separator was measured.The results showed that,the measured results were in good agreement with the numerical simulation.The circulating mixing exhibited excellent effect when the inlet and the outlet of the liquid flow were on the same side of the tank or water was injected into the downstream pipe of the pump.Moreover,fuel-water mixing was uniform at 0.2 MPa pump outlet pressure,and stable water content was kept within the range of 90 × 10-6 to 130 × 10-6 specified by the airworthiness standard.