Papers by Keyword: Pressure

Abstract: During the ongoing operation of the hydraulic system you need a drive control information capable of maintaining fitness. Existing methods for assessing the technical condition of the hydraulic system require dismantling the hydraulic units and their research on test rigs. These methods are expensive, time consuming and do not provide a quick assessment of the technical condition. The aim of the study is to present the possibilities of using the evaluation of technical aviation hydraulic drive method which involves the use of objective information from the aircraft's flight control. In the proposed method, the carrier of information to the ongoing evaluation of the technical condition of the hydraulic system aviation as a whole is the pressure prevailing in it. With pressure and its features is inextricably bound up time. This relationship may be obtained directly from the objective flight control of the aircraft. The greatest credibility and the diagnostic value of two control parameters are obtained from the flight control objective. The first time the air pressure drop in the hydraulic drive from the top to the bottom of the measured value of the measured value after switching off the power unit. The second time the pressure falls below a certain value, and its return to the values ​​of the movement during the hydraulic motor. The method enables the ongoing assessment of the technical condition of the hydraulic system is a fast and costless.

Abstract: This paper explored the effects of pressure on contacts between layers of organic photovoltaic cells with poly (3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT:PCBM) as the active layer. The contacts between the layers are modeled using analytical concepts and finite element models. The potential effects of surface roughness and dust particles are modeled along with the effects of lamination pressure and adhesion energy. The results show that, increased pressure is associated with decreased void length or increased contact length. The contacts associated with the interfaces between the active layer and the hole/electron injection layer poly (3,4-ethylenedioxythiophene: poly styrenesulphonate (PEDOT.PSS) and Molybdenum trioxide (MoO₃) are also compared. The implications of the results are discussed for the design of stamping/lamination processes for the fabrication of organic photovoltaic cells.

Abstract: Pressure garment is a standard non-surgical treatment for hypertrophic scar caused by burn injury. However, the main problem identified was the non-uniform pressure distribution due to the complexity of the contour at the facial area. Therefore, padding was developed to produce more efficient pressure distribution. This study used 3D scanning apparatus to obtain the cross sections of the facial area. The padding was developed using 3D modeling software which act as an insert to fill the gaps at the contact area of the garment and facial areas. The result shows that by inserting the padding underneath the garment, the pressure outputs indicate an acceptable pressure range with the suitable reduction factor for the head garment fabrication.

Abstract: The paper proposes to realize a simulative analysis following the theoretical notions regarding the hydraulic jump, at flow of fluids through open channels, when open a plane penstock, which is located in a trapezoidal channel. A penstock is formed from a plan panel with upright movement in supports, with the possibility of adjustment a fluid flow by means of a handling device.

Abstract: In the case of electrochemical discharge machining (ECDM), the number of influence factors is very high, and the complete determination of a mathematic pattern is very complicated, as proved by the time passed since the application of this processing technology and absence (for the time being) of such a system. The paper presents the method of random balance which allows influence factors hierarchization, depending on the amplitude of the effect they have on the response variable. The main influence factors will be considered: current intensity, voltage, electrode-tool – workpiece pressure, electrolyte supply intensity, relative velocity between the electrode-tool and the workpiece, electrode-tool thickness. The following response functions (performance criteria) were determined: processing productivity, processed surface roughness, flatness deviation. The experiment was made on an electrochemical discharge machining (ECDM) processing machine with a electrode-tool, stratified disk by introducing the electrolyte in it. The semi-finished material is alloy steel X40CrMoV5-1, and the material of the electrode-tool is generally use steel S235JR.

Abstract: This paper presents a case study of water flow over the chute spillway type for the Mengkuang Dam expansion project. It governs the surplus water from the dam to the downstream area. However, flows were driven by gravity along the curvature and vertical direction which cause unpredictable flow direction along the chute. Its cause’s thickening of turbulence, changing the velocity, pressure and depth of the water along the spillway. This study was simulated using a physical model with geometrical scale of 1:20. After some test conducted on the spillway, eleven locations on the spillway were selected for the test based on observation for the study. For each location, there were five points in a line with equal distance. Manometers were installed on six locations of the spillway. The water level, velocity and pressure were measured at every point for 100, 1000, 10000 years and PMF design discharge of the spillway. Several critical occurrences on the spillway such as turbulent and cross-wave were presented in this paper.

Abstract: The mathematical model of Francis turbine, operating at variable speed hydrounit, has created. The results of numerical modeling are fully consistent with the physical representation of the behavior of the hydraulic turbine in dynamic modes.

Abstract: This article conceptually reviews the technological process of heat network intervening substation’s operation process. It presents the substation’s operation process optimization method to increase the system energy efficiency at large. Experimental data, that prove the effectiveness and expediency of suggested heat network operation methods, are presented in a graphic form.

Abstract: Study on the flow and combustion behavior inside gas turbine combustor used in thermal power plant is described in this paper. The combustion process takes place using synthetic gas and emphasis is given to the effect of pressure variation on flame profile, temperature distribution and emissions as compared to the conventional combustion using methane. The operating pressure of the can-type combustor varies in the range of 1-10 atm. while the syngas composition is assumed to have fixed values of 10% CH₄, 55% CO, 30% H₂ and 5% N_2. Preliminary result shows that the flow inside the can-combustor is highly swirling which indicates good mixing of fuel and air prior to the entrance of the mixture to the main combustion zone. The temperature distribution at combustor mid plane show identical pattern for pressure range between 1-10 atm for both maximum and average temperature magnitude.

Abstract: This work aims to investigate the infiltration of a CaCO₃ filled resin in fibrous porous media (resin transfer molding process) using the PAM-RTM software. A preform of glass fiber mat (fraction 30%), with dimensions 320 x 150 x 3.6 mm, has been used in rectilinear injection experiments conducted at room temperature and injection pressure 0.25, 0.50 and 0.75 bar. The polyester resin contain 0% and 40% CaCO₃. The numerical results were evaluated by direct comparison with experimental data. The flat flow-front profile of the rectilinear flow was reached approximately half length of the mold. It was observed, that the both velocity infiltration and permeability have decreased with increasing the CaCO₃ content, thus, increasing the time to processing of the composite material.