The article presents the result of tests of a single segment of a prototype water turbine, performed in order to determine its shaft power output as a function of rpm, and to verify the declared performance. The results have been compared with the outcomes of numerical calculations performed, for the same conditions, with the use of FLUENT software. The work presents information of crucial importance for presenting the process of testing the piece in question, such as: test environment, properties of the test piece, testing equipment used, as well as the methodology and the course of hydromechanical measurements, along with the characteristics of the results obtained. Then, the measurement results are discussed and analyzed. Conclusions are presented as well. Analysis of the results, taking into consideration the physical image of phenomena occurring in the case of flow-devices, such as water turbines, has made it possible to define other, important characteristics of the turbine, such as: output, shaft torque and efficiency, as a function of rpm and head of turbine. Test results have confirmed the expected mechanical and power-related properties of the turbine and have proved the numerical flow modeling model used effective.
A brief description of the prospects concerning new applications of the turbine discussed has been presented as well
The article describes participation of Mi-2 helicopters in both military and civilian operations at sea. Although the multipurpose Mi-2 rotorcraft were not designed to operate in the harsh environment over the sea, they became - in the second half of the 1960s and in the 1970s - a standard type performing a wide array of tasks at sea. Modern turboshaft engines, a favorable weight-to-power ratio and a dual engine configuration were all factors enabling safe flight over the sea, at considerable distances from land. The specialized Mi-2RM variant designed by WSK PZL Świdnik provided the Naval Aviation with an opportunity to establish, in the 1st half of the 1970s, a unique marine air rescue system. The last Mi-2RM used for rescue missions was decommissioned as late as in 2010, although at that stage it was only used for aircrew training purposes. The Navy was also using the Mi-2Ch variant tasked with creating smokescreens to conceal vessels and port facilities. General purpose variants of the helicopter were used to transport people and goods. They also performed well during patrolling missions and while identifying various types of contamination.
As far as civilian use of the helicopters is concerned, Mi-2 versions equipped with special purpose on-board systems supported scientists in the exploration of the Antarctica at two stations of the Polish Academy of Science. The Maritime Authority in Gdynia was also using its own Mi-2 helicopter for over 30 years - until 2015 - for patrolling the Gdańsk and Puck Bays and waters around the Hel Peninsula. The missions were focusing primarily on detecting potential contamination of the coastal areas.
In the former Soviet Union, civilian Mi-2 variants were (and still are) standard equipment of deep sea icebreakers operating in the Arctic and around the North Pole. The machines are mainly used for safety purposes, as well as for transporting scientists and groups of extreme tourists. Approximately a dozen Mi-2 purchased from Russia in the mid-1990s, in turn, were used by the Aviation Force of the Mexican Navy. Unfortunately, no further details regarding their use are available.
In the article, the author presents the wide-scale use of Mi-2 helicopters in the different entities subordinated to the Minister of Interior - from the introduction of the design, until the present. Insights are presented pertaining to the early stages of the helicopter’s service life within the structures of the 103rd NJW MSW Aviation Regiment in the 1960s. The article describes selected aspects related to the introduction of the design, training, operational use and problems encountered. The service life of Mi-2 helicopters operating within the structures of the Ministry of Interior ended upon liquidation of the Ministry’s Aviation Detachment. That is when another chapter in the history of the helicopters was started, this time operated within the structures of the Police and Border Guard forces, where their service life has not been fully used up until this day. The paper describes the reality of every-day use to perform specific tasks, presents the location of aerodromes, touches upon a shift in the philosophy behind the use of the helicopters, and describes their strong and weak points. The PZL-Kania helicopter has been also presented, being a modernized version of the Mi-2, and still used in Poland within the aviation forces of the Ministry of Interior and Administration.
The article presents an aerodynamic concept of UAV in the gyrodyne configuration, as a more efficient one than the currently used UAV airframe configuration applied for monitoring tasks of power lines and railway infrastructure. A sample task which is realised by conceptual gyrodyne based on monitoring aerial power lines was characterised and described. The assumed idea of UAV was shown in comparison to the currently used aircraft configuration presented in the introduction. Referring to momentum theory, hover efficiency of the multicopter and the helicopter was evaluated. In relation to the helicopter, an initial draft of the airframe conception accompanied by a description of advantages of the gyrodyne configuration was exposed. Problems related to the gyrodyne configuration were emphasised in the summary.
Tomasz Seredyn, Adam Dziubiński and Piotr Jaśkowski
The article describes a computational study, using CFD models, of droplet spray dispersal in the wake of a ‘Turbo Kruk’ airplane up to 500 m downstream. The CFD Reynolds-averaged Navier-Stokes (RANS) models use a Lagrangian (droplet phase) and Eulerian (fluid phase) procedure to predict the droplet trajectories trough the turbulent aircraft wake. The methods described in the work have the potential to improve current models for aerial spraying and will help in the development of new spraying procedures. In this study, the CFD models are used to describe the phenomenon of sprays released from atomizers mounted on the plane. A parametric study of the aircraft model examines the effects of crosswind on the aircraft’s vortex structures and the resulting droplet trajectories. The study shows, that such influence is underestimated in the current models. A comparison of the present results to AGDISP predictions is provided.
The paper presents results of simulation calculations concerning an influence of stiffness of blade-hub connection on rotor loads and blades deflections in hover, level flight and pull up maneuver. The three versions of rotor are considered with articulated, elastic and stiff connections of blades and hub. The blades with the same distributions of stiffness, mass and the same aerodynamic characteristics are applied for all rotor cases. The rotor loads are calculated applying Runge-Kutta method to solve the equations of motion of deformable blades. According to the Galerkin method, the parameters of blades motion are treated as combination of considered blade bending and torsion eigen modes. The results of calculations indicate for possibility to generate the greater rotor control moments and to improve helicopter maneuverability in the case of applying the non-changed blade of articulated rotor combined with elastic rotor hub.
The purpose of this text is to demonstrate an operation of a compressed air system designed for high air flow laboratories and wind tunnels. Development of such air system is a challenge due to unusual requirements (simultaneous supply of several users having different requirements and necessity to provide extremely high flows) which have to be address by means of adequate compressed air storage capacity and sophisticated control system. Each stage of the design process is going to be described, focusing on the selection of air compressors, air receivers and air dryers, followed by an insight into a development of the control system. The air system being described in this paper was successfully implemented at the Institute of Aviation in Warsaw improving the quality of the compressed air supply and simplifying the research planning.
Gyroplanes, as ultralight aircraft, are popular transport vehicles recently. Ultralight aircraft flights take place at a low altitude – their noise is not without effect on people and nature. The localization of the sources of noise and a possibility to decrease the noise of an gyroplane are described in this paper. The rules of design and exploitation of gyroplanes do not define the limits of emitted noise.
Gyroplanes are not noisy aircraft vehicles but for their silencing the knowledge about the sources and frequency range of noise is necessary. The goal of the conducted measurement was to determine the gyro-plane noise properties and the noise measurement methods. The evaluation of the noise sources was made by acoustic beamforming and the directional emission with single microphones at various engine speeds.
The supplement of these tests should be the rotor noise measurement but that investigation should be performed on a special stand, on which the rotor propulsion noise would not disturb the measurement.
The Active Gurney Flap (AGF) is a small, flat tab cyclically deployed and retracted at lower surface of the rotor blade near its trailing edge. It is expected that the device may improve performance of modern helicopters. The main goal of presented investigations was to develop research methodology and next to use it in studies on phenomena occurring in the flow around helicopter-rotor blades equipped with AGF. Conducted CFD simulations aimed at validation of the developed methodology as well as at significant supplementing and extension of results of experimental research. Simplified sensitivity analysis has been conducted aiming at determination of geometric and motion-control parameters of the AGF, optimal from point of view of helicopter-performance improvement. Fully three-dimensional simulations of the rotor flight aimed at determination of flight conditions, in which the use of Active Gurney Flaps could significantly improve the rotorcraft performance.
This article presents selected results of I-31T propulsion tests, obtained in the framework of EU project ESPOSA (Efficient Systems and Propulsion for Small Aircraft). I-31T aircraft, as a testbed, was fitted with 180 kW turboprop engine TP100. The scope of the work include results of ground and in-flight tests of engine compartment cooling suitability. The purpose of the cooling tests was to prove that temperatures of the propulsion components are within limits set by the engine manufacturer for the engine type in the most disadvantageous conditions on the ground and in flight up to aircraft maximum altitude, maximum ambient temperature and after standard engine shutdown. Engine oil cooling is beyond the scope of this work.