scholarly journals Dynamic Behavior Analysis of Non-Contacting Hydrodynamic Finger Seal Based on Fluid-Solid-Interaction Method

2018 ◽  
Vol 153 ◽  
pp. 07005
Author(s):  
Hua Su ◽  
Jiru Wang
Keyword(s):  
High Pressure ◽  
Dynamic Behavior ◽  
High Speed ◽  
Gas Flow ◽  
Dynamic Performance ◽  
Low Pressure ◽  
Structure Design ◽  
Structural Deformation ◽  
Dynamic Performance Analysis ◽  
Fluid Solid Interaction

Finger seal is an advanced compliant seal and can be utilized to separate high (HP) and low pressure (LP) zones in high speed rotating shaft environment. The work to be presented concerns the dynamic behavior of a repetitive section of a two-layer finger seal with high-and padded low-pressure laminates. The dynamic performance of the finger seal are analyzed by the coupled fluid-solid-interaction (FSI) simulations. By using the commercial software ANSYS-CFX, the numerical simulation results of interactions between the gas flow and fingers structural deformation are described when the radial periodic excitation from the shaft applies to the finger seal. And the gas film loading capacity, gas film stiffness and leakage varied with time are put forward in different working conditions. Compared with the dynamic performance analysis results based on equivalent dynamic method, the FSI dynamic analysis shows some different characteristics which are more accordance with actual circumstance. Moreover, it is shown that under low pressure differential and high rotation speed the non-contacting finger seal with advance features both in sealing effectiveness and potential unlimited life span can be obtained by rational structure design. But for the non-contacting finger seal with circumferential convergent pad working in high pressure and low rotating speed conditions, it is difficult to improve the sealing performance by the way of changing the structure parameters of finger seal. It is because the high pressure plays a major role on this sealing situation.

Structure design and dynamic performance analysis of a high speed miniature lathe

2013 ◽  
Vol 9 (2) ◽  
pp. 119
Author(s):  
Hua dong Yu ◽  
Li meng Wang ◽  
Xiao zhou Li ◽  
Jin kai Xu ◽  
Qing yong Shi
Keyword(s):  
Performance Analysis ◽  
High Speed ◽  
Dynamic Performance ◽  
Structure Design ◽  
Dynamic Performance Analysis

Dynamic Performance Analysis on High-Speed Railway Continuous Girder Bridge

2011 ◽  
Vol 280 ◽  
pp. 186-190
Author(s):  
Shou Tan Song ◽  
Ji Wen Zhang ◽  
Xin Yuan
Keyword(s):  
High Speed ◽  
Moving Load ◽  
Damping Ratio ◽  
Dynamic Performance ◽  
Wheel Load ◽  
Dynamic Coefficients ◽  
Bridge Structures ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Dynamic Performance Analysis

The dynamic performance of continuous girder under the train in a series of speed is studied through examples, and the main conclusions are given in the following. The resonance mechanism of continuous girder is similar to simply supported beam. The vehicle wheel load forms regular moving load series, which induces periodical action and resonance of the bridge. The damping ratio of bridge itself has less effect on the amplitude at the loading stage, but significant effects appear when the load departs from the bridge. The count of continuous spans also has less impact on the dynamic coefficients, so three continuous spans can be adopted for calculation and analysis. Span and fundamental frequency have significant influence on dynamic coefficients of bridge structures. To extend the span of the bridge structure can reduce the dynamic coefficient while keeping its frequency invariant. The fundamental frequencies of different bridges are corresponding to certain resonant speeds, which calls for the attention in the design.

Research on the Kinematics Simulation of Out-Moving Jaw Crusher Based on Nastran

2013 ◽  
Vol 433-435 ◽  
pp. 63-66
Author(s):  
Jiang Yong
Keyword(s):  
Simulation Model ◽  
Simulation Analysis ◽  
Dynamic Performance ◽  
Theory Model ◽  
Structure Design ◽  
Side Plate ◽  
Jaw Crusher ◽  
Kinematics Simulation ◽  
Motion Characteristics ◽  
Dynamic Performance Analysis

In this paper, out-moving jaw crusher machine is regarded as the research object and we established the simulation model of virtual prototype based on Nastran. Through the simulation analysis of the movement process, trajectories of moving jaw side plate and a movable jaw toggle plate and related parameters were obtained and compared and verify the simulation model and theory model. The results show that: the simulation model reflects the motion characteristics of the theoretical model well. So it provides theoretical reference for improvement of dynamic performance analysis and structure design of jaw crusher and has important application value in engineering.

Experimental Investigation of the Tip Clearance Flow for an Axial Flow Fan Rotor Using a PIV System

2004 ◽  
Author(s):  
Xiaocheng Zhu ◽  
Wanlai Lin ◽  
Zhaohui Du
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Low Pressure ◽  
Tip Clearance ◽  
Tip Leakage Flow ◽  
Discrete Vortex ◽  
Tip Leakage Vortex ◽  
Tip Leakage ◽  
Ventilation Fan ◽  
Good Agreement

The flow field in the tip region of an axial ventilation fan is investigated with a PIV (Particle Image Velocimeter) system at the design condition. Characteristics of a ventilation fan are an extreme low-pressure difference and a large tip clearance with a low rotating speed. Flow fields with three different tip clearances are surveyed on three different circumferential planes, respectively. The phase-locked average method is used to investigate the generation and the development of a tip leakage vortex. The result from PIV system is compared with that from a PDA (Particle Dynamics Anemometer) system. Both data are in good agreement. The structure of the tip leakage vortex for the rotor is illustrated. The characteristic of a leakage vortex is described in both velocity vectors and vortical contours. It is found that the tip leakage flow for a low speed and a low pressure ventilation fan also has a chance to roll up into a discrete vortex at three different tip clearances, which is similar to high speed and high-pressure compressors and turbines. When the tip clearance increases, the scope and the location variation for the tip leakage vortex increase. Finally, the trajectories of the tip leakage vortex by the experimental measurement are compared with predictions from the existing models for high speed and high-pressure compressors and turbines. A good agreement is obtained.

Drilling Riser Design and Analysis for Deepwater Applications

2013 ◽  
Author(s):  
Yongming Cheng ◽  
Tao Qi
Keyword(s):  
High Pressure ◽  
Production Systems ◽  
Dynamic Performance ◽  
Design Procedure ◽  
Dynamic Strength ◽  
Low Pressure ◽  
Strength Analysis ◽  
Global Dynamic ◽  
Analysis Methodology ◽  
Riser Design

A riser is a fluid conduit from subsea equipment to surface floating production systems such as spars, TLPs, and semi-submersibles. It is a key component in a drilling and producing system. Drilling risers include the applications in marine drilling (low pressure) and tie-back drilling (high pressure). This paper discusses drilling riser design and analysis for a deepwater application. This paper first discusses the configuration of marine drilling and tie-back drilling risers. It then presents the drilling riser design procedure and analysis methodology. The riser design and analysis cover the riser tensioner setting, marine operation window, strength and fatigue, etc. A marine drilling riser example is used in the paper to demonstrate the design and analysis for a deepwater application. This paper shows the dynamic strength analysis results for the riser. It then identifies governing locations for the riser design. A tie-back drilling riser example is also provided to illustrate its global dynamic performance. This paper finally discusses the design and analysis challenges of a drilling riser for a deepwater application.

scholarly journals Venturi Wet Gas Flow Modeling Based on Homogeneous and Separated Flow Theory

2008 ◽  
Vol 2008 ◽  
pp. 1-25 ◽  
Author(s):  
Fang Lide ◽  
Zhang Tao ◽  
Xu Ying
Keyword(s):  
High Pressure ◽  
Pressure Drop ◽  
Gas Flow ◽  
Flow Model ◽  
Separated Flow ◽  
Flow Theory ◽  
Low Pressure ◽  
New Correlation ◽  
Wet Gas ◽  
Low Pressures

When Venturi meters are used in wet gas, the measured differential pressure is higher than it would be in gas phases flowing alone. This phenomenon is called over-reading. Eight famous over-reading correlations have been studied by many researchers under low- and high-pressure conditions, the conclusion is separated flow model and homogeneous flow model performing well both under high and low pressures. In this study, a new metering method is presented based on homogeneous and separated flow theory; the acceleration pressure drop and the friction pressure drop of Venturi under two-phase flow conditions are considered in new correlation, and its validity is verified through experiment. For low pressure, a new test program has been implemented in Tianjin University’s low-pressure wet gas loop. For high pressure, the National Engineering Laboratory offered their reports on the web, so the coefficients of the new proposed correlation are fitted with all independent data both under high and low pressures. Finally, the applicability and errors of new correlation are analyzed.

A Model for the Estimation of Pressure Ripple in Tandem Gear Pumps

2015 ◽  
Author(s):  
Mattia Battarra ◽  
Emiliano Mucchi ◽  
Giorgio Dalpiaz
Keyword(s):  
High Pressure ◽  
Dynamic Behavior ◽  
Low Pressure ◽  
Variable Pressure ◽  
Geometrical Parameters ◽  
Gear Pump ◽  
Helical Gears ◽  
Pressure Stage ◽  
Outlet Pressure ◽  
Pressure Ripple

The present paper addresses the development of a lumped parameters model used to analyze the dynamic behavior of a so-called tandem gear pump. The pump is composed of two coaxial stages, both with external gears: a high pressure stage with spur gears and a low pressure one with helical gears. In particular, the paper deals with the modelling and the analysis of the phenomena bound to the pressure distribution around the gears, since they have the most important effect in the dynamic behavior of the pump. The pressure variation in the inlet and outlet chambers, the variable pressure in the trapped volume as well as the pressure evolution from the low to the high pressure chamber is estimated based on the Euler’s approach. The model is developed in Matlab environment. Attention is particularly focused on the description of the methodology adopted for modelling the low-pressure stage, constituted by helical gears, and its influence on the calculation of the pump geometrical parameters. The results provided by the numerical model are compared with experimental measurements in terms of outlet pressure ripple and volumetric efficiency under different working conditions. The results of the validation can be considered satisfactory. Predicted pressure ripple is shown and the effects of interconnections between stages are analyzed studying the outlet pressure ripple in the frequency domain as well.

Static and Dynamic Performance Analysis and Improvement of Pillar in Vertical Drilling Machine

2011 ◽  
Vol 48-49 ◽  
pp. 1106-1111
Author(s):  
Wei Huang ◽  
Jun Qiu ◽  
Xiao Hui Zhu
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Dynamic Performance ◽  
Structural Deformation ◽  
Model Parameters ◽  
Drilling Machine ◽  
Deformation Characteristics ◽  
Pillar Structure ◽  
Dynamic Performance Analysis ◽  
Element Theory

Based on finite element theory, pillar structure of the model parameters was established, and analyzed its static and dynamic performance. At the same time, the structural deformation of pillar load and deformation characteristics were analyzed. The choosing shape method was used to get the improvements in pillar. The Improved models were done modal analysis, and got their natural frequencies.

Effect of Side Feed Pressurization on the Dynamic Performance of Gas Foil Bearings: A Model Anchored to Test Data

2008 ◽  
Author(s):  
Tae Ho Kim ◽  
Luis San Andre´s
Keyword(s):  
Test Data ◽  
High Speed ◽  
Gas Flow ◽  
Dynamic Performance ◽  
Rotor Speed ◽  
Mass Distributions ◽  
Foil Bearings ◽  
Feed Pressure ◽  
Run Up ◽  
Forced Cooling

Comprehensive modeling of gas foil bearings (GFBs) anchored to reliable test data will enable the widespread usage of these bearings into novel high speed turbomachinery applications. GFBs often need a forced cooling gas flow, axially fed through one end of the bearing, for adequate thermal management. The paper presents rotordynamic response measurements on a rigid rotor supported on GFBs during rotor speed run-up and coastdown tests with the GFBs supplied with increasing feed gas pressures to 2.8 bar. Rotor speed run-up tests to 35 krpm show that bearing end side feed gas pressurization delays the onset speed of rotor subsynchronous whirl motions. The test data validate closely predictions of the threshold speed of instability and whirl frequency ratio derived from a GFB model that implements the axial evolution of gas circumferential flow velocity as a function of the imposed side feed pressure. Rotor speed coastdown tests from 25 krpm with a low feed pressure of 0.35 bar evidences a nearly linear synchronous rotor response for small and moderately large imbalance mass distributions. A structural FE rotordynamics model integrates linearized synchronous speed GFB force coefficients and predicts synchronous responses, amplitude and phase angle, agreeing with the test data. The analysis and measurements demonstrate the profound effect of end side, feed gas pressurization on the rotordynamic performance of GFBs.

Finite Element Analysis and Optimization of Structure for Large Blanking Machine Equipment during High-Speed Blanking

2011 ◽  
Vol 697-698 ◽  
pp. 176-181
Author(s):  
Shu Bo Xu ◽  
K.K. Sun ◽  
Cai Nian Jing ◽  
Guo Cheng Ren
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optimal Design ◽  
High Speed ◽  
Dynamic Performance ◽  
Design Stage ◽  
Beam Structure ◽  
Element Analysis ◽  
Blanking Process ◽  
Dynamic Performance Analysis

This paper reviews the background and significance to investigate the high-speed speed blanking process modeling simulation and optimization of large blanking machine equipment for CNC uncoiling, leveling and shearing line. And a powerful tool has been providing to of heavy machinery optimal design specifications. The finite element model of beam structure has been established by using a three-dimensional modeling software UG NX4.0 CAD and finite element analysis software ANSYS. Then the static and dynamic characteristics results of the whole beam structure have been simulated. On the basis of analysis results, the optimal static and dynamic performance of square cross-section of the beam structure has been obtained. Drawings at the design stage of large blanking machine equipment for NC uncoiling, leveling and shearing line, the use of finite element theory and modal analysis theory, the structure of the blanking machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important.

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