Aviation Technologies

The conventional pitot-static tube’s accuracy in measuring indicated airspeed is compromised by its longitudinal inclination during forward flight, causing errors when the angle surpasses a critical threshold. This study aimed to propose and assess new designs for pitot-static tube ports to mitigate the angle of attack. Modifications, such as enlarging the inlet cross section, altering the tube port’s leading surface angle, and introducing new inlet openings, were implemented in five prototypes. After 2D CFD simulations, these prototypes were 3D printed, and experiments were conducted in a wind tunnel across angles from 0° to 55° at three airflow speeds. CFD results indicated increased error with larger inlet diameters and revealed an oscillating error phenomenon for multiple inlet openings. Experimental tests contradicted expected accuracy issues with extended diameters, suggesting superior characteristics at higher angles of attack. An oscillating error of pitot-static tubes with multiple holes was affirmed. The study targeted a pitot-static tube port design with a maximum 5% error in airspeed measurement within attack angles from 0° to 40°, showing promise for vertical takeoff and landing vehicle airspeed measurement during horizontal forward flight.The conventional pitot-static tube’s accuracy in measuring indicated airspeed is compromised by its longitudinal inclination during forward flight, causing errors when the angle surpasses a critical threshold. This study aimed to propose and assess new designs for pitot-static tube ports to mitigate the angle of attack. Modifications, such as enlarging the inlet cross section, altering the tube port’s leading surface angle, and introducing new inlet openings, were implemented in five prototypes. After 2D CFD simulations, these prototypes were 3D printed, and experiments were conducted in a wind tunnel across angles from 0° to 55° at three airflow speeds. CFD results indicated increased error with larger inlet diameters and revealed an oscillating error phenomenon for multiple inlet openings. Experimental tests contradicted expected accuracy issues with extended diameters, suggesting superior characteristics at higher angles of attack. An oscillating error of pitot-static tubes with multiple holes was affirmed. The study targeted a pitot-static tube port design with a maximum 5% error in airspeed measurement within attack angles from 0° to 40°, showing promise for vertical takeoff and landing vehicle airspeed measurement during horizontal forward flight.

The proposed technology introduces a rotary flap system for thrust vectoring of electric fan propulsion units, primarily intended for unmanned aircraft applications. The system consists of an electric fan enclosed in a cylindrical housing with an axially rotatable cover equipped with a movable flap mechanism. Through the combination of rotational and flap movements driven by dedicated actuators, the system enables omnidirectional thrust vectoring, allowing dynamic redirection of the propulsion force. This approach provides improved maneuverability, flight control capabilities, and enhanced operational flexibility for aircraft utilizing electric fan propulsion systems.

With the expanding electrification in all sectors of transport, it is necessary to look for new efficient solutions for propulsion systems for use in air transport. One of the approaches can be the use of electric ducted fans (EDFs), especially in, but not limited to, the case of unmanned aerial vehicles with vertical takeoff and landing. This concept has been known for several decades but has been used very little and therefore has been almost unexplored. This opens up opportunities for investigating the performance characteristics, electrical consumption or efficient thrust vectoring of EDFs with respect to their design and operational use. The presented study therefore deals with the influence of the EDF design change on its performance characteristics. These design changes mainly concerned the geometry of the cowling, i.e., reduction and increase of outlet cross section, and arrangement of fans, i.e., one- and two-rotor specification. The comparison was based on measuring of vertical thrust and power consumption during static testing. The results showed that the increasing outlet is the most suitable construction for the generation of vertical thrust during static testing, considering the specifically used EDF construction arrangement. Based on the findings, it can also be concluded that EDFs are a suitable option for use in unmanned aircraft as a competition to other propulsion systems.With the expanding electrification in all sectors of transport, it is necessary to look for new efficient solutions for propulsion systems for use in air transport. One of the approaches can be the use of electric ducted fans (EDFs), especially in, but not limited to, the case of unmanned aerial vehicles with vertical takeoff and landing. This concept has been known for several decades but has been used very little and therefore has been almost unexplored. This opens up opportunities for investigating the performance characteristics, electrical consumption or efficient thrust vectoring of EDFs with respect to their design and operational use. The presented study therefore deals with the influence of the EDF design change on its performance characteristics. These design changes mainly concerned the geometry of the cowling, i.e., reduction and increase of outlet cross section, and arrangement of fans, i.e., one- and two-rotor specification. The comparison was based on measuring of vertical thrust and power consumption during static testing. The results showed that the increasing outlet is the most suitable construction for the generation of vertical thrust during static testing, considering the specifically used EDF construction arrangement. Based on the findings, it can also be concluded that EDFs are a suitable option for use in unmanned aircraft as a competition to other propulsion systems.

Vertical Take-off and Landing Unmanned Aerial Vehicles (VTOL UAVs) are operated at low flight levels, close to the ground, where they are exposed to meteorological conditions, which are difficult to predict and can cause severe degradation of their aerodynamic, performance and flight characteristics. Of these meteorological conditions, icing is one of the most dangerous for the operation of VTOL UAVs. Although icing poses significant safety and operational risks, it has not yet been taken into account in their operation and there are no certified and verified anti-icing and de-icing solutions against it. The aim of this work is to propose a concept together with testing methodology, which would allow to determine the influence of individual meteorological conditions of icing on selected performance characteristics of propulsion systems of VTOLUAVs. Testing and exposure of propulsion systems to icing conditions took place in the climatic chamber. Several series of measurements were performed in the climatic chamber, in which the propulsion systems were exposed to a temperature of 15, of −5, of −10 and of −15°C and a flow of super-cooled water droplets of 1.43 g/s. The mutual comparison of the performed measurements made it possible to determine the influence of individual conditions on the decrease of the thrust, the increase of the consumed electric current and the occurrence of vibrations.