scholarly journals Experimental and Numerical Research on Flow-Induced Vibration in Valves

2017 ◽  
Vol 13 (2) ◽  
Author(s):  
Asmaa Ali Hussein
Keyword(s):  
Finite Element ◽  
Flow Rate ◽  
Vortex Shedding ◽  
Flow Characteristics ◽  
Operating Mode ◽  
Structural Vibration ◽  
Piping System ◽  
Flow Induced Vibration ◽  
Finite Element Software ◽  
Operation Conditions

Abstract   All central air conditioning systems contain piping system with various components, sizes, material, and layouts. If such systems in operating mode, the flow in piping system and its component such as valves can produce severe vibration due to some flow phenomenon’s. In this research, experimental measurements and numerical simulation are used to study the flow-induced vibration in valves. Computational fluid dynamics (CFD) concepts are included with one-way and two-way fluid-structure interaction concepts by using finite element software Package (ANSYS 14.57). Detection analysis is performed on flow characteristics under operation conditions and relations with structural vibration. Most of real geometrical, operational, and boundary conditions are simulated to obtain best similarity with real operation conditions. Comparisons performed between experimental data and numerical results (one-way and two-way simulation) to verify the results. The main conclusion was drawn from the study that the dominant source of vibration for valve is the water pulsation in addition to amount of water hammering. In addition, the main source of water pulsation in globe valve is the vortex shedding and pressure difference between upstream and downstream of valve. The vibration amplitude was increased with increasing flow rate until to be maximum when the flow rate around 30% and then decreased until flow rate reaches to around 85% and then trends to be constant. Keywords: Flow-induced vibration, vortex shedding, pressure pulsation, valve, finite element, ANSYS, fast Fourier transform (FFT).

scholarly journals STUDY ON ARRANGEMENT OF COOLING WATER PIPE TO CONTROL HYDRATION HEAT OF CONCRETE IN BEAM OF CABLE-STAYED BRIDGE

2021 ◽  
Vol 30 (2) ◽  
Author(s):  
Long Liu ◽  
Saisai Yu ◽  
Wentao Xu ◽  
Zhilong Wang
Keyword(s):  
Finite Element ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Hydration Heat ◽  
Inlet Temperature ◽  
Mass Concrete ◽  
Water Pipe ◽  
Finite Element Software ◽  
Joint Section

The box girder joint section of the Yangtze River Highway Bridge is taken as the research background, and the finite element software MIDAS/FEA is used to simulate the hydration heat of concrete to the layout of cooling water pipe in building mass concrete. The finite element calculation results are in well agreement with the measured data. On this basis, the influence of changing the diameter and distance of the cooling water pipe, the inlet temperature and the flow rate on the temperature of hydration heat is studied. The results show diameter of the cooling water pipe and inlet temperature have a significant effect on the temperature of hydration heat. The change of water flow rate has little effect on the temperature of hydration heat. It provides a reference for the layout of the same concrete cooling water pipe arrangement.

scholarly journals Effects of operation conditions and suction pipeline parameters on flow characteristics and metering accuracy for selective catalytic reduction air-assisted urea dosing system

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041987419
Author(s):  
Shudong Yang ◽  
Xiwei Pan ◽  
Youcheng Shi ◽  
Yinshui Liu
Keyword(s):  
Mathematical Model ◽  
Selective Catalytic Reduction ◽  
Flow Rate ◽  
Catalytic Reduction ◽  
Flow Characteristics ◽  
Flow Stability ◽  
Oxides Of Nitrogen ◽  
Pump Speed ◽  
Operation Conditions ◽  
Discharge Pressure

Selective catalytic reduction is the main technology to reduce oxides of nitrogen of diesel exhaust. As an important part of the selective catalytic reduction system, the air-assisted urea dosing system regulates the flow rate by adjusting the pump speed, and the flow rate and its metering accuracy directly affect the efficiency of oxides of nitrogen conversion. A mathematical model coupled with the air-assisted urea dosing system and the suction pipeline was built, and the influences of the discharge pressure, pump speed, suction pipeline length, and diameter on the flow characteristics and metering accuracy of the air-assisted urea dosing system were analyzed. The flow rate and metering accuracy of a prototype of the air-assisted urea dosing system were tested under different conditions on a test rig. Results show that the flow stability and metering accuracy of the prototype elevate with increasing the discharge pressure when the prototype has no overfeeding, and it gets down under any discharge pressure when the prototype occurs overfeeding. The flow stability and metering accuracy of the prototype improve with increasing the pump speed, and increase significantly when the suction pipeline length becomes shorter and the diameter gets larger. The metering accuracy of the prototype can achieve to ±2% by optimizing the suction pipeline parameters. The experimental results prove that the proposed mathematical model is effective.

The Analysis of Rotary Kiln Thermal Characteristics Based on ANSYS and FLUENT

2013 ◽  
Vol 834-836 ◽  
pp. 1523-1528
Author(s):  
Xiao Yan Song ◽  
Qin Fan
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Rotary Kiln ◽  
Mechanical Response ◽  
Coupling Effect ◽  
Interpolation Method ◽  
Combustion Process ◽  
Gas Temperature ◽  
Finite Element Software ◽  
Operation Conditions

In this paper, the FLUENT finite element software is used to simulation analyze the rotary kiln, kiln gas combustion process and gas-solid coupling effect. The kiln and rotary kiln of gas temperature field is calculated and then imported into the ANSYS software as an initial condition to complete the reconstruction of the temperature field and using the node interpolation method to carry out thermal stress analysis. Through the joint simulation analysis based on FLUENT and ANSYS finite element software, the analysis of rotary kiln combustion process, the heat transfer and the mechanical response of the structure can be implemented under the same condition, making the simulation results of rotary kiln more related to practical operation conditions. The method and results presented have significant theoretical guidance for the research and development of new types of rotary kiln.

Study on the Structural Dynamic Characteristics of Sand Washing Tower Based on ANSYS

2014 ◽  
Vol 578-579 ◽  
pp. 850-853
Author(s):  
Kun Zhao ◽  
Wei Hua Zhu ◽  
Feng Zhu ◽  
Chun Lin Huang ◽  
Xia Hua
Keyword(s):  
Finite Element ◽  
Theoretical Calculations ◽  
Recurrence Formula ◽  
Structural Vibration ◽  
Structural Dynamic ◽  
Finite Element Software ◽  
Structural Problems ◽  
Tower Structure ◽  
Structural Dynamic Characteristics ◽  
Vibration Modal

In this paper, we depart from the basic vibration equation deduced from Vibro sand tower structure recurrence formula. Using ANSYS finite element software to simulate the red sand of the top ten tower structural vibration modal. Of which the first two modal solutions in accordance with the conventional prismatic cantilever closer to theoretical calculations, the results of the finite element solution proved authentic, we provide a theoretical basis for the use of finite element methods for solving the structural problems of sand washing tower.

scholarly journals Simulation Study on the Blocking Effect and Vibration Reduction Characteristics of Acoustic Black Hole in Thin Plate

2020 ◽  
Vol 6 (4) ◽  
pp. 223-231
Author(s):  
Z. Liu ◽  
Y. Zhou ◽  
A. Golyanin
Keyword(s):  
Finite Element ◽  
Black Hole ◽  
Noise Reduction ◽  
Thin Plate ◽  
Vibration Reduction ◽  
Structural Vibration ◽  
Energy Concentration ◽  
Element Analysis ◽  
Finite Element Software ◽  
Reduction Effect

Recently, more and more scholars have devoted themselves to researching new methods of vibration reduction and noise reduction by manipulating the elastic waves in the structure to achieve the purpose of vibration reduction and noise reduction. To this end, a new type of ‘acoustic black hole’ structure is proposed, which reduces structural vibration while avoiding problems such as mass increase. In this paper, the vibration damping performance of the structure is mainly calculated by finite element software, and the energy concentration effect of the thin plate containing the acoustic black hole is verified by finite element analysis. A thin plate structure with four acoustic black holes is proposed. The calculation shows that the structure has obvious vibration reduction effect, and the vibration reduction effect can reach more than 20dB at high frequency.

A Perturbation Technique for Flow-Induced Vibration Control

2002 ◽  
Author(s):  
L. Cheng ◽  
Y. Zhou ◽  
M. M. Zhang
Keyword(s):  
Vibration Control ◽  
Vortex Shedding ◽  
Bluff Body ◽  
Perturbation Technique ◽  
Structural Vibration ◽  
Control Element ◽  
Local Perturbation ◽  
Cylinder Surface ◽  
Laser Vibrometer ◽  
Flow Induced Vibration

This paper presents a novel technique to perturb the vortex shedding from a bluff body and subsequently suppress the flow-induced structural vibration. The essence of the technique is to create a local perturbation on the surface of a bluff body using piezoelectric actuators. Experiments were carried out in a wind tunnel. A square cylinder of a height h, flexibly supported on springs at both ends, was allowed to vibrate only in the lift direction. Three actuators were embedded underneath one side, parallel to the flow, of the cylinder. They were simultaneously activated by a sinusoidal wave, thus causing the cylinder surface to oscillate. The structural displacement Y and flow velocity u were simultaneously measured using a laser vibrometer and a single hot-wire, respectively. When the vortex shedding frequency ƒs synchronized with the natural frequency of the dynamic system, Y was estimated to be about 0.08h. This displacement collapsed to 25% once the actuators were excited at a normalized frequency ƒh/U∞ = 0.1 (U∞ is the free-stream velocity) and amplitude of 0.028h. The laser-illuminated flow visualization captured drastically weakened vortices shed from the cylinder. Spectral analysis of the Y and u signals points to the fact that the imposed perturbation has altered the spectral phase at ƒs between fluid excitation and structural vibration from 0 to π, and meanwhile decreased the spectral coherence at ƒs from 0.65 to 0.15. It is expected that the perturbation technique presently investigated will have an important role to play in the flow-induced vibration control, especially with the active control element assimilated into the system.

Flow Characteristics of Vortex Shedding Flowmeters

1980 ◽  
Vol 13 (5) ◽  
pp. 166-170 ◽  
Author(s):  
F. A. Inkley ◽  
D. C. Walden ◽  
D. J. Scott
Keyword(s):  
Flow Rate ◽  
Vortex Shedding ◽  
Kinematic Viscosity ◽  
Flow Characteristics ◽  
Experimental Results ◽  
Viscosity Range ◽  
Oil Blend

Experiments were carried out on three 2in diameter, commercial vortex shedding flowmeters using a gravimetric flow rig with flows up to 22 l/s. Water, kerosine and a kerosine/spindle oil blend were used at test liquids and accuracy curves of meter factor against flow rate were obtained at temperatures between 20° and 50°C, covering a kinematic viscosity range of 0.5 to 4.3 cSt. This paper presents a discussion of these experimental results and shows that the accuracy of the various flowmeters is not significantly affected by changes in liquid properties over the range of conditions investigated.

Flow Induced Vibration of a Steam Control Valve in Middle-Opening Condition

2005 ◽  
Author(s):  
Ryo Morita ◽  
Fumio Inada ◽  
Michitsugu Mori ◽  
Kenichi Tezuka ◽  
Yoshinobu Tsujimoto
Keyword(s):  
Pressure Fluctuation ◽  
3D Structure ◽  
Flow Characteristics ◽  
Control Valve ◽  
Piping System ◽  
Flow Induced Vibration ◽  
Valve Body ◽  
Weak Support ◽  
Side Load ◽  
Attached Flow

In some cases, a steam control valve in a power plant causes a large vibration of the piping system under partial valve opening. For rationalization of maintenance and management of a plant, it is favorable to optimize the valve geometry to prevent such vibration. However, it is difficult to understand the flow characteristics in detail only from experiments because the flow around a valve has a complex 3D structure and becomes supersonic (M>1). Therefore, it is useful to combine experiments and CFD (Computational Fluid Dynamics) for the clarification of the cause of vibration and optimization of valve geometry. In previous researches involving experiment and CFD calculation using “MATIS” code, we found that an asymmetric flow attached to the valve body (named “valve-attached flow”) occurs and pressure increases where the valve-attached flow collides with the flow from the opposite side under the middle opening condition. This high-pressure region rotates circumferentially (named “rotating pressure fluctuation”) and causes cyclic side load on the valve body. However, because we assumed the valve support is rigid, we cannot clarify the interaction between the rotating pressure fluctuation and the valve vibration when the valve stiffness is small. Thus, in this paper, we conducted flow-induced vibration experiments on a valve with a very weak support and investigated the characteristics of the vibration mode under the middle-opening condition. As a result, under the specific lift condition of the region where rotating pressure fluctuation occurs, lock-in phenomena between the rotating pressure fluctuation and the valve vibration occur and large-amplitude vibration can be seen.

scholarly journals Low-Cycle Fatigue Crack Initiation Simulation and Life Prediction of Powder Superalloy Considering Inclusion-Matrix Interface Debonding

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4018
Author(s):  
Shuming Zhang ◽  
Yuanming Xu ◽  
Hao Fu ◽  
Yaowei Wen ◽  
Yibing Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Crack Initiation ◽  
Life Prediction ◽  
Damage Mechanics ◽  
Low Cycle Fatigue ◽  
Fatigue Crack Initiation ◽  
Fatigue Loading ◽  
Interface Debonding ◽  
Damage Evolution Equation ◽  
Finite Element Software

From the perspective of damage mechanics, the damage parameters were introduced as the characterizing quantity of the decrease in the mechanical properties of powder superalloy material FGH96 under fatigue loading. By deriving a damage evolution equation, a fatigue life prediction model of powder superalloy containing inclusions was constructed based on damage mechanics. The specimens containing elliptical subsurface inclusions and semielliptical surface inclusions were considered. The CONTA172 and TARGE169 elements of finite element software (ANSYS) were used to simulate the interfacial debonding between the inclusions and matrix, and the interface crack initiation life was calculated. Through finite element modeling, the stress field evolution during the interface debonding was traced by simulation. Finally, the effect of the position and shape size of inclusions on interface debonding was explored.

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