This paper presents a mathematical model with 3 degrees of freedom developed in Matlab/Simulink environment for numerical simulation of aircraft ground dynamics. As a reference aircraft Airbus A319 midsize commercial passenger aircraft has been chosen. The model takes into account the forces and moments generated by the aircraft (aerodynamics and thrust) and the forces generated in the landing gear tires. The model was validated against a simplified takeoff run model derived from aircraft flight records. For qualitative model assessment two cases of curvilinear aircraft ground motion were simulated and analyzed. In these simulations the aircraft weight and center of gravity position were varied as a parameter of operational relevance.

The paper presents the results from testing a Volkswagen 1.9 D diesel engine on a test bench to work on gas-diesel cycle with oxyhydrogen gas mixture. Experimental research is done to show the impact of oxyhydrogen gas mixture on engine consumption and environmental indexes such as: fuel and specific fuel consumption; carbon monoxide; carbon dioxide; oxides of nitrogen; smoke emissions. The oxyhydrogen gas mixture delivered to the engine intake manifold with constant flow rate. The results are obtained under research contract № 6524-4/2016.

This paper studies the developments of urban air mobility by a focus on the configurations and flight mechanisms of the different vehicles in this field. This s

The absence of accurate performance data is a common problem with most civilian unmanned aerial vehicle (UAV) power plant producers. The reasons for this are the small size of most of the manufacturers and the high price of precise wind tunnel testing and computer simulations. To overcome this problem at Dronamics Ltd., with support from the Department of Aeronautics of TU-Sofia, a mobile test stand for evaluation of electric power plants for unmanned aircraft was developed. The stand may be used statically, or may be installed on the roof of an automobile. The measurement system of the stand is based on popular hardware that is used in radio controlled models and in general automation. The verification of the measurement system is performed by comparing static test results with data published by the manufacturer of the tested electric motor. Tests were carried out with 2 different types of propellers and the results were compared with published results for common propellers as well as with results of theoretical studies. The results are satisfactory for practical applications. The use of this type of test stands can be a cheap and effective alternative for research and development start-up companies like Dronamics.

Experimental studies of a helicopter rotor in ground effect aim to quantify the effect of the ground proximity on their performance. As a result of the performed experimental work, dependencies between the produced thrust (T) and torque (Q), varying the rotor’s distance to the ground (H) and blade pitching angle (8) are drawn from one perspective, and the correlations between the generated thrust (T) and torque (Q), and their corresponding coefficients C_T and C_Q, varying the distance to the ground (H) and blade pitching angle (8) at several fixed rotational frequencies (n). Additionally, a dependency between the generated relative thrust coefficients (C_TIGE/C_TOGE) against the relative distance to the ground (H/D) at a fixed rotational frequency of 750 RPM, varying the blade inclination angle (8) is also derived and presented in this study. In summary, the research successfully quantified the effect of the rotor’s static characteristics in the ground effect zone and posed topics for further research.

This paper examines developments in urban air mobility (UAM), the configurations and flight mechanisms of different aerial vehicles. Despite the interest generated around UAM, there seems to be a gap in the literature concerning a systematic comparative analysis of different configurations, especially regarding their appropriateness for given applications, performance under fault conditions, and potential in even more foresightful but neglected designs. The other problems standing in the way of current UAM technologies are limited payload capacity, endurance, and energy efficiency, all of which work against successful commercialization. This study, therefore, considers a representation of 53 of the more prominent UAM aircraft, classified into a number of groups, paving a way for the in-depth study of important specifications such as range, speed, endurance, cargo capacity, number of passengers, and dimensions. Twelve general UAM configurations are identified, along with their advantages, disadvantages, and fault tolerance. Some underutilized designs are highlighted as worthy of more attention due to their potential. An attempt is made to link UAM configurations to specific applications, such as transportation, emergency response, and cargo delivery, in order to provide specific recommendations for each application. This work challenges standard design thinking, thus inciting designers to explore unusual avenues. The outcome is a useful analysis for researchers and engineers to look at UAM technologies in a different light while opening up possibilities for unconventional and creative designs.