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Gheorghe Samoilescu, Dumitru Iorgulescu, Robert Mitrea and Laura D. Cizer

References [1] Magnusson.T, Meeting- A boats behaviour and important parameters, 2017 [2] TMQ International- How does an autopilot work [online]. Available at: http://tmqeurope.com/information/how-does-an-autopilot-work [3] www.Standard ship test and inspection plan, procedures and data base, U. S. Departament of the Navy Carderock Division, Naval Surface Warface Center,1999-2017 [4] Procedure of testing steering gears on ship, 2017 https://www.marineinsight.com/guidelines/procedure-of-testing-steering-gears

Open access

Marcin Kurdelski and Andrzej Gębura

Abstract

The paper deals with selected issues related to operation of steering disks designed for helicopters that are currently in operation of the Air Force of the Republic of Poland. The attempt is made to present a prediction of hazards to the transmission gear of that helicopter where the forecast is based on a theoretical analysis of mechanical phenomena as well as the statistical and diagnostic analyses. The major attention is paid to the opportunity to diagnose hazardous locations of the helicopter steering disk with use of a non-destructive FAM-C method originally developed by ITWL. The method is based on tracking of frequency modulation parameters generated by the on-board AC generator. The examination does not require the installation of any additional sensor since the transmission is subjected to neither additional load nor distortions of the rotation speed occur.

The authors of this study disclosed the initial results from diagnostic measurements as well as snapshots taken during the disassembling of steering disks from Mi-24 and Mi-17 helicopters that were operated under heavy duty conditions of military missions in Iraq and Afghanistan. They also suggested an easy and cheap method for field checking of the steering disk bearing by photogrammetric measurements. It is also demonstrated that the method of diagnostic investigations can be also spread onto other helicopter makes and types.

Open access

Anna Witkowska and Roman Śmierzchalski

). Adaptive Steering of Ships-A Model Reference Approach to Improved Maneuvering and Economical Course Keeping , Ph.D. thesis, Delft University of Technology, Delft. Bibuli, M., Caccia, M. and Lapierre, L. (2007). Path-following control of fully-actuated surface vessels in the presence of ocean currents, Proceedings of the IFAC Conference on Control Applications in Marine Systems, Bol, Croatia , (on CD-ROM). Casado, M.H. and Ferreiro, R. (2005). Identification of the nonlinear ship model parameters based on the turning test trials and the

Open access

Jan Koralewski

Influence of hydraulic oil viscosity on the volumetric losses in a variable capacity piston pump

The variable capacity piston pumps are elements of the great power and highest energy efficiency hydrostatic drives. They are used in the drive systems of ship equipment such as deck cranes, steering gears, main propulsion of smaller vessels. The laboratory and simulation investigations of the influence of liquid viscosity on the variable capacity displacement pump energy losses have not been so far performed.

The paper presents results of the investigations of impact the hydraulic oil viscosity has on the volumetric losses in a piston pump operating in the full range of its capacity and oil pressure.

Open access

Ionut Daniel Geonea, Nicolae Dumitru and Alexandru Margine

for People with Motor Disa bilities, 1997. 4. Kong D., Nonlinear Contact Analysis of Gear Teeth for Malfunction Diagnostics, Conference and Exposition on Structural Dynamics , 2008. 5. Modak G. S., Review Article: Evolution of a Stair-Climbing Power Wheelchair, IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE), pp. 36-41, 2009. 6. Pires G., Autonomous Wheelchair for Disabled People, Proc. IEEE Int. Symposium on Industrial Electronics (ISIE97), Guimarães, 797-801, 1997. 7. Rajasekar R., Design and fabrication of staircase

Open access

Tomasz Abramowski and Tadeusz Szelangiewicz

Numerical analysis of influence of selected elements on effectiveness of streamline rudder

During designing steering gear for large fast transport ships (e.g. container carriers), shipowners usually put forward strong demands concerning ship manoeuvrability. It means that streamline rudders should be characterized by a high effectiveness, i.e. fast increasing values of lifting force in function of rudder angle and large values of lifting force related to rudder area. As gabarites of streamline rudder depend on a form and draught of stern part of ship's hull, an improvement of rudder effectiveness can be reached by an appropriate selection of rudder profile and application of additional elements to rudder blade.

This paper presents results of numerical investigations (by using CFD methods) of hydrodynamic forces acting on rudder blades of the same gabarites but based on different profiles. Such calculations were also performed for selected rudder blades fitted with additional elements intended for the improving of rudder effectiveness.

Open access

Kamil Urbanowicz

Fluids and Structures, 28, 1, pp. 434-456, 2012. 11. Pezzinga G.: Evaluation of time evolution of mechanical parameters of polymeric pipes by unsteady flow runs , Journal of Hydraulic Engineering, 140, 12, paper 04014057, 2014. 12. Qiu Y. et al.: Suppressing water hammer of ship steering systems with hydraulic accumulator . Proc IMechE Part E: J Process Mechanical Engineering, Vol. 228 (2), pp. 136–148, 2014 13. Reddy H.P. et al.: Estimation of decay coefficients for unsteady friction for instantaneous, acceleration-based models , Journal of

Open access

Ionut Daniel Geonea, Nicolae Dumitru and Alexandru Margine

Abstract

In this paper is presented the design solution and experimental prototype of a wheelchair for disabled people. Design solution proposed to be implemented uses two reduction gears motors and a mechanical transmission with chains. It’s developed a motion controller based on a PWM technology, which allows the user to control the wheelchair motion. The wheelchair has the ability of forward – backward motion and steering. The design solution is developed in Solid Works, and it’s implemented to a wheelchair prototype model. Wheelchair design and motion makes him suitable especially for indoor use. It is made a study of the wheelchair kinematics, first using a kinematic simulation in Adams. Are presented the wheelchair motion trajectory and kinematics parameters. The experimental prototype is tested with a motion analysis system based on ultra high speed video cameras recording. The obtained results from simulation and experimentally tests, demonstrate the efficiency of wheelchair proposed solution.

Open access

Grzegorz Skorek

Abstract

A control system with a proportional directional throttling control valve or a directional control servo valve, controlling a cylinder (linear hydraulic motor) is used in the ship steering gear drive, in the controllable pitch propeller control, in the variable capacity pump control system for hydraulic deck equipment motors or fixed pitch propellers in small ships (for example ferries). Energy savings in a constant capacity pump operation can be achieved by means of overflow valve controlled by the oil outlet pressure between the directional throttling control valve and the cylinder. Although structural volumetric losses cannot be eliminated in such a system, but it is possible to reduce considerably structural pressure losses, mechanical losses and volumetric losses in the pump, and mechanical losses in the cylinder too. The paper discusses these energy savings using an earlier developed by Paszota mathematical model of losses in elements, the energy efficiency of the system and the operating range of the cylinder. The paper also presents a comparison of the energy behavior of two widespread structures of hydrostatic systems: a standard individual systems with a throttling steering fed by a constant capacity pump. Both system solutions are described and equations of the total efficiency η of the system are presented. Diagrams of energy efficiency of two hydraulic systems working at the same parameters of a speed and a load of hydraulic linear motor, which were different due to structure and ability of energy saving, were presented and compared.

Open access

Lucjan Guma, Marcin Przywarty and Rafał Gralak

Evaluation of Failure Probability of Ships on the Baltic Sea by Means of Simulation Model and Statistical Data

The ship technical failures contribution in overall number of navigational accidents are significantly smaller than those caused by human factor but in safety analysis they cannot be neglected. The paper presents stochastic modeling the technical failures of ships with respect of most important ship systems such as main engine, power generators and steering gear. The data for simulation was obtained from analysis of ships statistical data of polish owners. Obtained results could be useful for estimation of transport loses or potential environmental threats and planning the response action against them.