Influence of Parallel Capacitance on Pressure Response for Non-stationary Flow

Práce se zabývá experimentálními a numerickými metodami pro stanovení vlivu paralelní kapacity na tlakovou odezvu při nestacionárním proudění. Je navržen hydraulický obvod pro měření požadovaných veličin potřebných ke stanovení vlivu paralelní kapacity na dynamiku hydraulického systému. Jsou vybrány vhodné snímače pro měření tlaku, průtoku a teploty. Je popsána metodika měření a užití diagnostického měřicího přístroje M 5060+. Je vytvořen matematický model hydraulického obvodu v programu Matlab SimScape Fluids, který odpovídá reálnému hydraulickému obvodu, na kterém probíhá experimentální měření. Jsou vyhodnoceny výsledky z experimentálního měření společně s numerickými metodami.This master thesis deals with the experimental and numerical methods for the evaluation of influence of parallel capacitance on pressure response for non-stationary flow. The hydraulic circuit for measuring required quantities, which are necessary to determine influence of parallel capacitance on the dynamics of the hydraulic system. There are created suitable sensors for measuring pressure, flow and temperature. The method of measuring and using of diagnostic measuring device M 5060+ is described. The mathematic model of the hydraulic circuit is created in Matlab SimScape Fluids program. This model is the equal as the real hydraulic circuit. The results from measuring and numerical methods are evaluated.338 - Katedra hydromechaniky a hydraulických zařízenívýborn

Static Characteristic of Proportional Pressure Relief Valve

Import 02/11/2016Práce se zabývá stanovením statických charakteristik proporcionálního přepouštěcího ventilu. Je navržen hydraulický obvod pro měření požadovaných veličin potřebných ke stanovení statických charakteristik. Jsou vybrány vhodné snímače pro měření tlaku, průtoku a teploty. Je popsána metodika měření a užití diagnostického měřicího přístroje M 5050. Jsou vyhodnoceny statické charakteristiky proporcionálního přepouštěcího ventilu TS58 – 20 (Hydraforce).This bachelor thesis deals with Static Characteristics of proportional pressure relief valve. The hydraulic circuit for measuring required quantities, which are necessary to determine static characteristic is designed. There are created suitable sensors for measuring pressure, flow and temperature. The method of measuring and using of diagnostic measuring device M 5050 is described. Static characteristics of proportional pressure relief valve TS58 – 20 (Hydraforce) are evaluated.338 - Katedra hydromechaniky a hydraulických zařízenívýborn

Experimental verification of pneumatic elements mathematical models in Matlab-Simulink Simscape

The paper deal with a mathematical model of a pneumatic system and simulation of its behaviour. In the Matlab-Simulink Simscape program, there are models of basic elements from which it is possible to build a model of the entire system. The article describes the gradual testing of pneumatic elements mathematical models on the base of comparison with experimental data.Web of Science20236363635

Experimental analysis of fluidic muscles

Fluidic muscles have been the subject of research since the 1930s to the present day. McKibben's muscle is one of the most common ones. This type is the basis for fluidic muscles already being used commercially. The power-to-weight ratio is one of their main advantages. The disadvantage is difficult handling. The article describes experimental verification of static characteristics of fluidic muscles. During muscle contraction, a tensile force is developed which changes as the length of the muscle changes. This dependence is experimentally verified. A measuring equipment for testing fluidic muscles of various lengths and diameters is designed and assembled. The device consists of a pneumatic circuit, where the output drive is a loaded fluidic muscle. The load of muscle is generated by a hydraulic cylinder. The results will be further applicable to fluidic muscle simulations.Web of Science20225763575

Simulation of parallel capacitance influence on the hydraulic system dynamics

This paper covers with experimental measurement and mathematical simulation of parallel capacitance influence on pressure response for non-stationary flow. The hydraulic circuit for measuring required quantities, which are necessary to determine of parallel capacitance influence on the hydraulic system dynamics. A part of hydraulic system is a long pipe, in which the parallel capacitance created by hydraulic hose is connected. A non-stationary flow is caused by fast closing of the seat valve, which is situated at the end of long pipe. Mathematical model is realized and verified in Matlab SimScape Fluids software for this hydraulic system

Braid Angle and its Influence on the Hydraulic Hoses Behaviour Under Pressure Loading

This paper deals with the experimental analysis of the effect of the braid angle on the behaviour of a hydraulic hose under pressure loading. The main structural elements of the hose are a rubber tube and a steel braid or spiral. The material of the braid and the number of braids influence the magnitude of the pressure load on the hydraulic hose. The angle of the braid affects the deformation of the hydraulic hose when the inner wall is loaded with fluid pressure. For hydraulic hoses, it is a requirement to maintain a neutral braid angle during manufacture to ensure a balance between axial and circumferential stresses under pressure loading. An experimental device was set up to measure the hoses. This device can be used to measure the diameter of the outer braid, the length and the tensile force of the hose in the axial direction and, where appropriate, to evaluate the angle of the outer braid of the hose as a function of the fluid pressure loading on the inner wall of the hose. The object of the research is to determine the effect of the braid angle on the behaviour of the hydraulic hose under pressure loading. Based on the measurements, the dependencies of the tensile force, the braid angle and the change in length of hydraulic hoses on the internal pressure were determined. In order to compare the measurement results, hydraulic hoses with different inner diameters and different numbers of braids or spirals were selected. Research background: Description of neutral braid angle, hydraulic hose geometry, tensile force of hose. Purpose of the article: Influence of braid angle on the hydraulic hoses behaviour under pressure loading. Methods: Experimental measurements. Findings & Value added: Determining of the change of length dependencies on the pressure, determining of the tensile force dependencies on the pressure

Simulation of parallel capacitance influence on the hydraulic system dynamics

This paper covers with experimental measurement and mathematical simulation of parallel capacitance influence on pressure response for non-stationary flow. The hydraulic circuit for measuring required quantities, which are necessary to determine of parallel capacitance influence on the hydraulic system dynamics. A part of hydraulic system is a long pipe, in which the parallel capacitance created by hydraulic hose is connected. A non-stationary flow is caused by fast closing of the seat valve, which is situated at the end of long pipe. Mathematical model is realized and verified in Matlab SimScape Fluids software for this hydraulic system

Experimental and Numerical Analysis of Leakage Characteristics of Proportional Directional Valve

This article deals with the experimental and numerical analysis of the leakage characteristics of the proportional directional valve. These characteristics describe the flow through the directional valve in the region of the center position of the spool valve. The element under investigation is a three-position four-way directional valve with zero overlap and feedback from the valve spool position. The actual valve spool position is sensed by an inductive position sensor and processed by integrated electronics. By means of an offset on the integrated electronics, it is also possible to set the center position of the valve spool. By moving the valve spool, the size and direction of the working fluid flow in both directions can be controlled. Internal leakage occurs due to axial and radial clearances between the spool and the sleeve. The magnitude of the axial clearances that occur at the control edges is investigated. The blocked-line pressure sensitivity curve, leakage flow curve and center flow curve are determined by experimental measurements. Depending on the experimental measurement, the correction of the center position of the valve spool is then made using offset. The flow through the control edges at the center position of the valve spool was simulated using Ansys Fluent software. Subsequently, the geometry of the flow simulation model is adjusted. The adjustment is made to take into account manufacturing tolerances. Finally, the simulated dependencies including the effect of manufacturing tolerances are compared with the measured and analytically determined characteristics. Research background: Spool valve description, mathematical equations, flow analysis through valve, radial and axial clearance. Purpose of the article: Effect of axial clearance on leakage characteristic. Methods: Experimental measurements, numerical simulation. Findings & Value added: Determining the range of the center flow curve as a function of manufacturing tolerance

Leakage Characteristics of Proportional Directional Valve

This paper deals with the analysis of leakage characteristics of the proportional directional valve. These characteristics distinguish a real directional valve from an ideal one. The ideal directional valve is characterized by zero leakage due to its perfect geometry. The investigated element is the three-position four-way proportional directional valve with zero spool lap and feedback from the spool position. The spool position is measured by the inductive position sensor and processed by external electronics. Internal leakage occurs due to axial and radial clearances between the spool and the sleeve. The magnitude of axial clearances that occur at throttle edges and their effect on the directional valve leakage is the subject of research. The blocked-line pressure sensitivity curve, the leakage flow curve and the center flow curve are determined by experiment. Individual characteristics are determined for different working fluid temperatures and different supply pressures. The flow through internal leaks in the center position of the valve spool is determined by analytical calculations. The flow through internal leaks is also simulated using the Ansys Fluent software. Subsequently, the geometry of the flow simulation model is modified to take into account manufacturing tolerances. From simulation results, the effect of the manufacturing tolerance magnitude on the internal leakage of the directional valve is evaluated. Finally, simulated dependencies are compared with experimentally determined characteristics