AERODYNAMIC PERFORMANCE OF BLADELESS DUCTED FAN BASED ON EJECTION EFFECT WITH DIFFERENT DESIGN VARIABLES

Based on the development needs for electrification, low noise, and high safety, this research ex-plores the application potential of bladeless ducted propulsion systems (BDPS) based on the ejection effect as a power device for aircraft. The bladeless ducted propulsion system uses a compressor to compress the airflow, which is then ejected at high speed through an annular slit. This high-speed air-flow generates low pressure near the inner wall surface, inducing the forward airflow to accelerate backward to obtain thrust. The system mainly comprises an energy device, compressor, air duct, and bladeless ducted propulsion. Firstly, this article provides a brief introduction to the main components of the bladeless ducted propulsion system. Then, based on momentum theory, it analyzes the propulsion characteristics of the bladeless ducted propulsion, deriving theoretical formulas for duct thrust, required power, and propulsion efficiency. It also studies the numerical simulation methods for bladeless ducted propulsion, using the RANS method as a basis to examine the effects of model complexity and grid quantity on propulsion characteristics and the differences between three-dimensional and two-dimen-sional configurations. Subsequently, the article investigates the impact of several important design var-iables on the propulsion performance of bladeless ducted propulsion and its flow mechanism. The study finds that design variables such as duct outlet area, inflow speed, and duct length significantly affect thrust characteristics and ejection ratio characteristics. Finally, ground principle flow spectrum tests are conducted to verify the bladeless ducted propulsion, confirming the significant suction effect of the fan.