Zbigniew Czyż

CFD MODEL OF THE CNG DIRECT INJECTION ENGINE

The paper presents CFD analysis of fuel flow in the CNG injector. The issues such a pressure drop along an injector channel, mass flow through the key sections of the injec tor geometry, flow rates, the impact of the needle shape on the deflection of the sprayed gas cone and the impact of the wall head are analyzed in the article. The simulation was made in the transient states conditions for full injection process, including the opening and closing of the injector. An injection time of 6 ms, velocity of 0.33 mm/ms and a l ift of 0.5 mm were selected for opening and closing of injector based on experimental test. The simulation shows that the volume inside the injector is a kind of fuel accumulator, and the opening process of the needle influence the flow parameters in an inlet cross-section after a certain time, depending on a channel cross section. The calculations allowed to select the ratio of an injector duct cross sectional area to the aperture area of the injection capable of the reducing pressure loss. The unusual location of the injector in the socket of a glow plug in the Andoria ADCR engine makes a stream be impaired by a part of the head. This research result would be useful in developing an injector construction which will be used for an investigation of CNG addition into diesel engine.

THE CHARACTERISTICS OF THE OPERATING PARAMETERS OF THE VERTICAL AXIS WIND TURBINE FOR THE SELECTED WIND SPEED

The article presents the results of examining a wind turbine on the vertical axis of rotation. The study was conducted in an open circuit wind tunnel Gunt HM 170 in the laboratory of the Department of Thermodynamics, Fluid Mechanics and Aviation Propulsion Systems at Lublin University of Technology. The subject of research was a rotor based on the patent PL 219985, with blades capable of altering the surface of the active area (receiving kinetic energy of the wind). The study was performed on appropriately scaled and geometrically similar models maintaining, relevant to the type of research, the criterion numbers. The studied rotors with different blade inclination angles were produced using a 3D powder printer ZPrinter® 450. The results of the conducted research were obtained for the flow velocity of 6.5 m/s and three inclination angles, 30°, 60°, and 90°, at variable rotational speed. The test equipment used in the study allows maintaining the required speed, recording velocity and torque, which in turn allows an engineer to measure such characteristics of torque and power as a function of rotor speed.

Analysis of the pre-rotation engine loads in the autogyro

The paper presents the analyzes of the pre-rotation engine loads in the Taurus autogyro manufactured by Aviation Artur Trendak from Poland. Based on the NACA-9 H-12 airfoil characteristics of the drag coefficient, on which the rotor blade was made, forces acting on the rotor during pre-rotation have been calculated. The paper presents the characteristics of the drag coefficient as a function of angle of attack for Re = 1,800,000 and Re = 2,600,000. For the speed range of 0 to 400 rpm torque resulting from the drag forces and the power required to drive the rotor were calculated.

EXPERIMENTAL INVESTIGATION OF THE IMPACT OF FLIGHT SPEED ON DRAG FORCE IN THE AUTOGYRO MODEL

The paper presents the experimental investigation of the impact of velocity on drag force in the autogyro model. One of the methods which simulate motion of the flying object consists of using a wind tunnel. In this case, test object is stationary and the motion of air is forced by e.g. a special fan. The costs related with renting and the wind tunnel service are still very high. In this paper, the motion of the autogyro with respect to the air, was produced by fixing this model with scale to measure the drag force on the passenger car roof. The position of the object relative to the vehicle was checked on the basis of numerical analysis of the airflow around this vehicle. Based on the investigations, the field of velocity and pressure, and air flow formed around the contour of the vehicle which have been chosen, were determined. In addition, the drag force characteristic was determined as a function of velocity and it was compared with the values from the numerical analysis. This research is a form of verifying opportunities for this type of research on vehicles. The conclusions derived from the analysis of the results will be used in the future to carry out further research.

Investigation of Aerodynamic Interference in a Multirotor by PIV Method

This paper presents part of the investigation into aerodynamics of the vertical take-off and landing multirotor. There are described the technology to design a research object and the Particle Image Velocimetry (PIV) setup to measure airflow around the aircraft. The around-the-aircraft speed distribution was investigated for an angle of attack of 0o and for four different configurations. The results are presented in form of vector velocity field of airflow on the plane of symmetry of the test object. The results enabled the characteristics of speed vs. the distance from the fuselage. It was observed that the push propeller and the main rotor impact the speed field around the fuselage.

THE AIR FLOW INFLUENCE ON THE DRAG FORCE OF A SPORTS CAR

ABSTARCT The paper presents the numerical analysis of the drag force generated on the body of a sports car, based on the CFD method in the Ansys Fluent program. The three-dimensional model of the vehicle was taken from an open CAD database. Based on this, a computational grid was developed, boundary conditions and a turbulence model were defined. As a result of the calculations, the pressure distribution on the individual body parts and the velocity distribution in selected cross sections were obtained. In the next part of the research, the simulation results are used to optimize the shape of the bodywork of different passenger vehicles in order to reduce the generated drag force.

Identification of Noise Generated by Driving Set of Autogyro Using an Acoustic Camera

The article discusses the advantages of using an acoustic camera to analyze noise distribution. Location of noise sources was based on example of an autogyro model. Tests were performed using a 16-microphone acoustic camera using Noise Inspector software. Acoustic maps and sound power levels for two aircraft operations conditions were obtained. The results obtained during the various states of the model work were compared.

Wind turbine operation parameter characteristics at a given wind speed

This paper discusses the results of the CFD simulation of the flow around Vertical Axis Wind Turbine rotor. The examined rotor was designed following patent application no. 402214. The turbine operation is characterised by parameters, such as opening angle of blades, power, torque, rotational velocity at a given wind velocity. Those parameters have an impact on the performance of entire assembly. The distribution of forces acting on the working surfaces in the turbine can change, depending on the angle of rotor rotation. Moreover, the resultant force derived from the force acting on the oncoming and leaving blades should be as high as possible. Accordingly, those parameters were individually simulated over time for each blade in three complete rotations. The attempts to improve the performance of the entire system resulted in a new research trend to improve the performance of working turbine rotor blades.