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The article describes the solution of a scientific problem that consists in expanding the functionality of the program “Calculation of the traction-economic and mass-specific characteristics of the power plant and aircraft motion parameters” through the introduction of additional algorithms and mathematical models for calculating the altitude-speed characteristics of screw aircraft power installations. At the same time, an internal calculation of the aircraft propeller thrust is used according to experimental aerodynamic coefficients, which makes it possible to increase the efficiency and reliability of complex theoretical studies of power plants of various types as part of aircraft at the stage of external design. A description is given of the developed algorithms: an algorithm for converting power on the output shaft of a gas turbine engine into thrust of an aircraft power plant; a mathematical model of a propeller that provides calculation of its thrust from experimental aerodynamic coefficients; an algorithm for determining the thrust of the power plant, taking into account the compressibility of the air and the interaction of the propeller and the elements of the airframe of the aircraft. Some features of the mathematical modeling of an aircraft propeller are revealed, in particular, the principle of propeller control by influencing the blade angle and rotational speed depending on the aircraft flight speed and a method for constructing the field of aerodynamic characteristics of an aircraft propeller in a wide range of blade angle and speed coefficient. In conclusion, the results of verification of the modified program are presented with an analysis of the obtained altitude-speed characteristics.

This paper delves into the effects of a toroidal propeller's geometrical characteristics on its thrust and efficiency. The focus is on three distinct numerical distributions: the outward inclination angle, the pitch angle, and the number of blades. The Reynolds-Averaged Navier–Stokes (RANS) method is employed to analyze the propeller's open-water performance, taking into account cavitation flow, and a test bed was constructed to verify the rationality of CFD simulation. The findings reveal that the toroidal propeller's efficiency and thrust coefficient initially increase with the outward inclination angle, followed by a decline; the angle of maximum efficiency is identified at 23.25°. A reduction in the pitch angle leads to a temporary rise in efficiency, which subsequently falls, accompanied by a continuous decrease in the thrust coefficient. The optimal selection angle should consider this to prevent negative thrust at lower advance coefficients, which could further impact overall efficiency. An increased number of blades elevates the thrust coefficient and reduces the force on each blade, yet has a minimal effect on efficiency. Additionally, the orthogonal test method was utilized to explore the interactions between these three parameters. The outcomes indicate that, in terms of final power, there is no significant interaction among the three parameters under investigation. However, notable interactions are observed between the pitch angle and the number of blades, the outward inclination angle and the pitch angle, and the outward inclination angle and the number of blades. Consequently, the study's findings facilitate the selection of parameter combinations that yield higher efficiency or thrust coefficients. [ABSTRACT FROM AUTHOR]

This paper aims to propose a simple, straightforward, yet robust test rig design to measure the static thrust magnitude for small propellers. Although there were advanced tools like multi-axis force or torque sensors, sophisticated equipment and complex mechanisms were required to capture the accurate thrust magnitude. Therefore, providing simple and effective test rig design for small-sized propellers is quite challenging. In this work, Pugh matrix analysis was used to evaluate three new designs of Propeller Thrust Measurement Rig (PMTR) and compare the designs against a benchmark model. The evaluation covered important design criteria during test operation, such as measurement accuracy, stability, ease of development, assembly, maintenance, versatility, electronic integration, airflow interference, adaptability for tilt angle studies, and resemblance to multicopter flight conditions. The results reveal that the PMTR-1 design scored the highest in the analysis and emerged as the most suitable candidate among the proposed designs. It showed potential superior performance in stability, ease of development and assembly, versatility, simplicity, airflow management, and adaptability for future studies. PMTR-3 demonstrated some potential but needs more enhancement in electronic integration and structural development. However, PMTR-2 faces significant potential challenges in providing stability, versatility, electronic integration, and adaptability for effective and safe operations. [ABSTRACT FROM AUTHOR]

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Navigation of cargo ships using icebreaker assistance is a common tactic in difficult icy conditions. The icebreaker makes the ice channel and the lone cargo ship, or the convoy, sail within the channel it has made. When the icebreaker or the vessel ahead stop before the insuperable ice obstacle, the danger of an emergency appears, namely, the collision with an icebreaker or the ship ahead, if the interval between them is not sufficient for effective braking and stopping, or for a way out in compact ice cover. To find the safe interval recommendation, it is necessary to carry out modelling of the ship manoeuvring: either braking or the leaving of the channel. In these modes of ship movement, the propeller operates in unusual modes: in reverse mode when braking, and in close to mooring mode when leaving the channel, which do not have analytical descriptions because of the detached flow of the blades. This paper describes a developed empirical method for the parameterization of the propeller thrust coefficient dependence upon the advance, based on diagrams for the design of the propellers, which were created from the test material of the serial propeller tests. Outcomes of the investigation will be applied for computer modelling of the ship's manoeuvring within the ice channel and the safe interval between the ship and an icebreaker evaluation in what follows.

In order to provide references for propeller selection and power system matching, it is necessary to understand the factors affecting propeller thrust. In this paper, a combination of static push test and theoretical analysis is adopted. On the basis of building a static thrust test system for airboat propeller, two types of propellers are tested under different parameters, and the effects of propeller speed, angle of pitch and number of blades on static thrust are analyzed. The results show that the greater the installation angle, the greater the propeller thrust, the faster the thrust of the pitch angle as the speed increases; the higher the speed, the faster the thrust rise; the thrust of the three blades is greater than the thrust of two blades, but the gap is not obvious at the low speed; at the same speed of propeller, the number of blades and pitch angles are all the same, the thrust characteristic of the wide type propeller is superior to the narrow type propeller. [ABSTRACT FROM AUTHOR]

This paper discusses the design and development of a laboratory scale remotely operated vehicle (ROV) using Lego Mindstorms. The prototype ROV is a compact unit built using a limited number of components and is suitable for underwater inspection using a web camera. The ROV's operational efficiency and performance was evaluated based on its ability to move forwards and backwards, ascending and descending rates, and turning radius with respect to motor speed. Reverse engineering was used to identify manoeuvring problems before modifications were made. The size of the propulsion motors and propellers to propel the ROV were calculated and recommended theoretically. [ABSTRACT FROM AUTHOR]