Search results for "Linder"
showing 10 items of 178 documents
The use of results of spectral analysis of synchronous generator output voltage for technical diagnostics.
2006
The method of technical diagnostics of ship diesel engine-generator installations is offered. Spectral-power diagnostic parameters of the synchronous generator voltage and currents are used. The electric machine in this case is the multipurpose sensor of diagnostic parameters. On these parameters it is possible to judge quality of course of working processes in diesel engine cylinder, its technical condition. This method is applicable to piston compressor installations with the electric drive.
Improving the Efficiency and Dynamic Properties of a Flow Control Unit in a Self-Locking Compact Electro-Hydraulic Cylinder Drive
2019
Abstract The introduction of low cost electric motor and drive solutions provides the possibility to design cost competitive compact speed-variable drives as potentially feasible alternatives to conventional valve-controlled solutions. A main drawback in existing self-contained drive technology is the power consumption in stationary load carrying situations. However, the recent introduction of compact self-locking drive topologies with separate forward and return flow lines allow to significantly minimize the power consumption, but introduces another problem. Dependent on the control of the flow device, a continuous, but lower power consumption compared to non-self-locking drive topologies …
An advanced numerical treatment of EM absorption in human tissue
2020
The numerical computation of local electromagnetic absorption at points within the human tissue is proposed by avoiding the mesh generation in the problem domain. Recently, meshless numerical methods have been introduced as an alter- native computational approach to mesh based methods. This is an important feature to generate competitive procedure able to provide final evaluations for large data amounts in real time. In this paper the smoothed particle hydrodynamics method is considered to compute the electromagnetic absorption. First experiments are performed in two dimension at single frequencies by considering incident TM plane wave on 2D cylinder simulating a simplified model of human t…
Electrolyte Flow and Temperature Calculations in Finite Cylinder Caused by Alternating Current
2006
The distribution of electromagnetic fields, forces and source term of temperature induced by an alternating axially-symmetric system of electric current in a cylinder of a finite length with 6 electrodes has been investigated and calculated in [2, 1].
Spark ignition feedback control by means of combustion phase indicators on steady and transient operation
2014
In order to reduce fuel cost and CO2 emissions, modern spark ignition (SI) engines need to lower as much as possible fuel consumption. A crucial factor for efficiency improvement is represented by the combustion phase, which in an SI engine is controlled acting on the spark advance. This fundamental engine parameter is currently controlled in an open-loop by means of maps stored in the electronic control unit (ECU) memory: such kind of control, however, does not allow running the engine always at its best performance, since optimal combustion phase depends on many variables, like ambient conditions, fuel quality, engine aging, and wear, etc. A better choice would be represented by a closed-…
KNOWN RESIDUAL STRESS SPECIMENS USING OPPOSED INDENTATION
2009
In order to test new theories for residual stress measurement or to test the effects of residual stress on fatigue, fracture, and stress corrosion cracking, a known stress test specimen was designed and then fabricated, modeled, and experimentally validated. To provide a unique biaxial stress state, a 60 mm diameter 10 mm thick disk of 316L stainless steel was plastically compressed through the thickness with an opposing 15 mm diameter hard steel indenters in the center of the disk. For validation, the stresses in the specimen were first mapped using time-of-flight neutron diffraction and Rietveld full pattern analysis. Next, the hoop stresses were mapped on a cross section of two disks usi…
Angle Displacement Robust Controller for the Port Plate of the Hydraulic Transformer
2013
The hydraulic transformer is used in the hydraulic system to enhance the efficiency. However, how to control the angle displacement of the port plate is becoming a critical issue because of the new structure of the hydraulic transformer. This paper presents a new method for the angle displacement control system. Firstly, the basic principle of the system is presented. Then, the disturbance which is mainly the friction torque between the port plate and the cylinder block is calculated to estimate the range. Furthermore, the guaranteed cost control (GCC) is analyzed and combined with the disturbance and the characteristics of parameter uncertainties. Finally, the proposed control method is co…
FE Calculation Methodology for the Thermodynamic Fatigue Analysis of an Engine Component
2006
Thermo mechanical fatigue problem is treated to define an analysis methodology permitting the strength evaluation by reliability viewpoint. The main difficulty is the lack of both theoretical and experimental information; consequently the problem is treated verifying continually the validity and the limits of the developing solution method. The main task of the activity described in this paper was the development of a numerical methodology, based on FE analyses, for the evaluation of the structural behavior of engine components subjected to thermo mechanical fatigue phenomena. The chosen application was the exhaust manifold of an IC engine; FE analyses were executed following the standard m…
Leakage-detection in blade pitch control systems for wind turbines
2012
The main contribution of the work is a systematic study evaluating the performance of different filters for leakage detection in pitch control systems. The effectiveness of the proposed methods is examined in a Matlab/Simulink real-time environment. The test bed consists of the following elements: hydraulic power unit, servo valve, two leakage bypasses, hydraulic cylinder, payload and xPC-based control system. The filters are tested with the state-augmentation and the hypothesis testing approaches. To our knowledge, the comparison of these different approaches has not been done previously for this type of application. The paper concludes on the accuracy and sensitivity of the leakage detect…
The Effect of Friction in Passive and Active Heave Compensators of Crown Block Mounted Compensators
2012
Abstract This paper studies the effects of friction model during passive and active heave compensation of offshore drilling equipment. The main purpose of heave compensation while drilling from vessels or semi-submersible platforms is to maintain the drilling operation unaffected by the wave induced motion. The investigated system is of an existing crown mounted compensator. A model of the system is developed which includes mechanics, hydraulics and pneumatics. The passive heave compensation scheme is described including force equalising hydraulic cylinders. In this paper the detrimental effect of friction on the heave compensation performance in both passive and active heave compensation i…