Hybrid uncertainty analysis on the aerodynamic performance of a ducted fan

With the rapid advancement of green aviation technologies, electrically driven ducted fans have seen widespread adoption in electric vertical takeoff and landing aircraft due to their high hover efficiency and low noise. However, uncertainties in manufacturing process and operation parameters can significantly affect thrust performance and introduce operational risks. Stochastic uncertain parameter and interval uncertain parameter are considered in this paper. The Polynomial Chaos Expansion integrated with the Legendre inclusion function is employed to analyze the aerodynamic performance of a ducted fan under hybrid uncertainty. The tip clearance is treated as a stochastic uncertain parameter, modeled as a normal distribution N (3.5, 0.12 2 ). The rotational speed is considered an interval uncertain parameter within the range of [2350, 2450] rpm. The hybrid uncertainty analysis shows that the lower and upper bound mean of the total thrust is [92.71 N, 100.96 N], and the lower and upper bound standard deviation is [0.666 N, 0.745 N], demonstrating noticeable performance deviation under hybrid uncertainty. In addition, statistical characteristics of the lower and upper bounds of total thrust are presented. The bound relative variance (BRV) of the overall performance is 5%, whereas the BRV of the ducted thrust increased to about 8% due to pressure variations near the lip region. Additionally, a hybrid uncertainty analysis for cruise condition has also been conducted.