Numerical investigation on conveying sensitivity of fuel supply devices to tilt angle in powder engines: Comparison of external versus built-in intakes

The fuel delivery laws of horizontal tanks are no longer adequate for efficient supply under complex flight conditions, while the supply characteristics of non-horizontal tanks are not sufficiently explored. In this work, the piston-driven fuel supply devices with external slit-shaped and novel built-in cube-, sphere-, and dome-shaped intakes were selected as the research objects. The conveying sensitivity of devices at different tilt angles was investigated using two-fluid model. The results indicate that as the tilt angle increases from 0° to 90°, the fluctuation in mass flow rate of powder under the cube-, sphere-, and dome-shaped intakes increases by about 53.8%, 46.6%, and 35.0%, respectively, while the slit-shaped intake decreases by about 1.0%. The gas under the built-in intake migrates from the head of the device to the outlet, while the gas under the external intake is distributed near the wall of the conical convergence section, and the fluctuations in pressure and relative pressure drop of the former are more intense than those of the latter. At varying tilt angles, the area of gas phase under external intake is approximately 15 times that of the built-in. At low tilt angles (0° and 30°), the variations in gas-solid velocities and powder concentration are similar for the dome- and slit-shaped intakes. As the tilt angle increases, the fluctuation in these two physical quantities in the cube- and sphere-shaped intakes is larger than in other cases. At a high tilt angle (90°), the built-in cube-shaped intake exhibits the least satisfactory supply performance.