Search results

1 – 10 of 23
Per page
102050
Citations:
Loading...
Access Restricted. View access options
Article
Publication date: 9 April 2018

Haibin Chen, Jie Zhu, Fangwei Xie, Xinjian Guo and Xudong Zheng

The purpose of this paper is to use the viscosity of fluid to transmit power known as the hydro-viscous drive (HVD) to research the effect of two-phase flow on transmission…

68

Abstract

Purpose

The purpose of this paper is to use the viscosity of fluid to transmit power known as the hydro-viscous drive (HVD) to research the effect of two-phase flow on transmission characteristics.

Design/methodology/approach

In this paper, a 3D computational model of oil film between friction pair was built to study the transmission characteristics of a two-phase oil film, and the distribution contours of pressure and temperature of oil film were investigated using the computational fluid dynamics technology.

Findings

The finding of the paper suggests that the distribution law of pressure and temperature of two-phase oil film is almost linear along the radial direction. However, since the physical phenomena near the outlet of the oil film are entirely different, there exists fluctuation. Meanwhile, the volume fraction of air was obtained at different rotation speeds, and the maximum value is 10.55 percent. Compared to the single-phase oil film, the torque transferred by the oil film is not linear with the rotation speed, its value decreases gradually.

Originality/value

This paper’s conclusions are very important for the study of HVD and its applications, which provide a new idea to further study the mechanism of oil film transmission and its cavitation. The development of fluid viscous speed clutch is dedicated to a large industrial fan and water pump speed regulation and energy saving. With the successful application of the technology, it will have more wide applications in different fields, such as, in steel, water, petrochemical, power plant of slag pump and exhaust fan.

Details

International Journal of Structural Integrity, vol. 9 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

Access Restricted. View access options
Article
Publication date: 1 October 2018

Fangwei Xie, Dengshuai Wang and Cuntang Wang

The purpose of this paper is to study the flow characteristics of damping control valve of shock absorber, and obtain the minimum driving current required under different working…

111

Abstract

Purpose

The purpose of this paper is to study the flow characteristics of damping control valve of shock absorber, and obtain the minimum driving current required under different working conditions.

Design/methodology/approach

Based on the simplified model of the internal structure of damping control valve and the theory of fluid mechanics, the mathematical model of the damping control valve driving current under rated load is established. The test bench was designed to study the relationship between flow characteristics and driving current of the damping control valve.

Findings

The results show that the minimum driving current of switching and flowrate show a linear relationship and the minimum current required for the 4-1 switching is the largest that means the minimum current as long as meets the 4-1 switching to meet the needs of all levels switching.

Originality/value

These results of the theoretical and experimental study provide a reliable guide and reference for the design and application of damping control valve.

Details

International Journal of Structural Integrity, vol. 9 no. 5
Type: Research Article
ISSN: 1757-9864

Keywords

Access Restricted. View access options
Article
Publication date: 1 October 2018

Fangwei Xie, Xinjian Guo, Diancheng Wu, Bing Zhang, Xudong Zheng, Dengshuai Wang and Yun Wang

In this paper, a kind of an oil groove structure which could improve the transmission torque of an oil film was designed, i.e. the width and depth of oil groove gradually decrease…

79

Abstract

Purpose

In this paper, a kind of an oil groove structure which could improve the transmission torque of an oil film was designed, i.e. the width and depth of oil groove gradually decrease with the increase in the radius.

Design/methodology/approach

Effects of the structural parameters of the oil groove on the hydro-viscous drive (HVD) characteristics with variable rotational speed were investigated by means of numerical calculation.

Findings

Research results show that with the decrease of the width and depth of the oil groove at the outer diameter, transmission torque increases, while the temperature is almost unchanged. Keeping the effective area unchanged, comparing the transmitted torque under the oil groove angle θ2 = 0.5° and θ2 = 4.5°, the former was almost 200 per cent of the latter; the torque transmitted with h2 = 0.05 mm was almost 150 per cent of that with h2 = 0.2 mm.

Originality/value

In this paper, the authors analyze the friction surface of the friction plate between the oil groove, oil distribution and oil film transfer torque from the oil groove structure parameters and found methods to improve the transmission torque. For the first time, the influence of the structural parameters of oil groove on the characteristics of HVD was studied under the condition of variable rotational speed, and a better method to improve the transmission torque was proposed.

Details

Industrial Lubrication and Tribology, vol. 70 no. 9
Type: Research Article
ISSN: 0036-8792

Keywords

Access Restricted. View access options
Article
Publication date: 17 August 2018

Fangwei Xie, Xudong Zheng, Yaowen Tong, Bing Zhang, Xinjian Guo, Dengshuai Wang and Yun Wang

The purpose of this paper is to study the working characteristics of hydro-viscous clutch at high rotational speeds and obtain the trend of flow field variation of oil film.

125

Abstract

Purpose

The purpose of this paper is to study the working characteristics of hydro-viscous clutch at high rotational speeds and obtain the trend of flow field variation of oil film.

Design/methodology/approach

The FLUENT simulation model of the oil film between the friction disks is built. The effect of variation of working parameters such as input rotational speed, oil flow rate and film thickness on two-phase flow regime and transmission torque is studied by using the volume of fluid model.

Findings

The results show that the higher the rotational speed, the severer the cavitation is. In addition, the two-phase flow region makes the coverage of oil film over the friction pairs’ surface reduce, which results in a decrease in transmission torque for the hydro-viscous clutch.

Originality/value

These simulation results are of interest for the study of hydro-viscous drive and its applications. This study can also provide a theoretical basis for power transmission mechanism of oil film by considering the existence of a two-phase flow regime consisting of oil and air.

Details

Industrial Lubrication and Tribology, vol. 70 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

Access Restricted. View access options
Article
Publication date: 4 September 2017

Fangwei Xie, Diancheng Wu, Yaowen Tong, Bing Zhang and Jie Zhu

The purpose of this paper is to study the influence of structural parameters of oil groove (such as central angle number, depth and so on) on pressure, flow, load capacity and…

155

Abstract

Purpose

The purpose of this paper is to study the influence of structural parameters of oil groove (such as central angle number, depth and so on) on pressure, flow, load capacity and transmitted torque between friction pairs of hydro-viscous clutch.

Design/methodology/approach

According to the working process of friction pairs of hydro-viscous clutch, mathematical models of hydrodynamic load capacity and torque transmitted by the oil film were built based on viscosity-temperature property. Then analytical solutions of pressure, flow, load capacity and transmitted torque were obtained; effects of central angle of oil groove zone and friction contact zone, oil film thickness, number of oil grooves on pressure, flow, load capacity and torque were studied theoretically.

Findings

The research found that the central angle of oil groove zone, number of oil grooves and oil groove depth have similar effects on flow, which means that with the increase of central angle, number or depth of oil grooves, the flow also increases; pressure in friction contact zone and oil groove zone drops along radial direction, whereas its value in oil groove zone is higher. With the increase of the central angle of oil groove zone, pressure in friction contact zone and friction contact zone rises, and the load capacity increases, whereas the transmitted torque drops. Number of oil grooves has little effect on load capacity. When the oil film thickness increases, its flow increases accordingly, whereas the pressure, load capacity and transmitted torque drops. Meanwhile, the transmitted torque decreases with the increase of number of oil grooves, whereas the oil groove depth nearly has no effects on transmitted torque.

Originality/value

In this paper, mathematical models of hydrodynamic load capacity and torque transmitted by oil film were built based on viscosity-temperature property in the working process of hydro-viscous clutch, and their analytical solutions were obtained; effects of structural parameters of oil groove on transmission characteristics of hydro-viscous clutch based on viscosity-temperature property were revealed. The research results are of great value to the theory development of hydro-viscous drive technology, the design of high-power hydro-viscous clutch and relative control strategy.

Details

Industrial Lubrication and Tribology, vol. 69 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Access Restricted. View access options
Article
Publication date: 26 September 2019

Zhibao Li, Fangwei Xie, Junyu Sun, Jie Zhu, Xudong Zheng, Xinjian Guo, Yun Wang and Yinqun Hua

The purpose of this paper is to study the temperature characteristics of hydro-viscous clutch with different structure of friction disks and obtain the distribution of film…

133

Abstract

Purpose

The purpose of this paper is to study the temperature characteristics of hydro-viscous clutch with different structure of friction disks and obtain the distribution of film temperature.

Design/methodology/approach

The mathematical model of oil film between friction disks with radial grooves is established. Based on the flow rate equation, the temperature rise equation of oil film is deduced. Considering two-phase flow, the temperature distribution in the oil shear stage and the effects of the ratio of inner radius to outer radius on film temperature rise is studied by using computational fluid dynamics (CFD) technology.

Findings

The results show that when input speed is constant, the increase in the ratio of inner to outer radius leads to an increase in the peak temperature and the decrease in the ratio results in a larger increasing rate of temperature.

Originality/value

These results are of interest for the study of hydro-viscous drive and its applications. This study can also provide a theoretical basis for the mechanism of temperature rise by considering the effect of two-phase flow.

Details

Industrial Lubrication and Tribology, vol. 72 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Access Restricted. View access options
Article
Publication date: 27 August 2021

Jianzhong Cui, Hu Li, Dong Zhang, Yawen Xu and Fangwei Xie

The purpose of this study is to investigate the flexible dynamic characteristics about hydro-viscous drive providing meaningful insights into the credible speed-regulating…

100

Abstract

Purpose

The purpose of this study is to investigate the flexible dynamic characteristics about hydro-viscous drive providing meaningful insights into the credible speed-regulating behavior during the soft-start.

Design/methodology/approach

A comprehensive dynamic transmission model is proposed to investigate the effects of key parameters on the dynamic characteristics. To achieve a trade-off between the transmission efficiency and time proportion of hydrodynamic and mixed lubrication, a multi-objective optimization of friction pair system by genetic algorithm is presented to obtain the optimal combination of design parameters.

Findings

Decreasing the engagement pressure or the ratio of inner and outer radius, increasing the lubricating oil viscosity or the outer radius will result in the increase of time proportion of hydrodynamic and mixed lubrication, as well as the transmission efficiency and its maximum value. After optimization, main dynamic parameters including the oil film thickness, angular velocity of the driven disk, viscous torque and total torque show remarkable flexible transmission characteristics.

Originality/value

Both the dynamic transmission model and multi-objective optimization model are established to analyze the effects of main design parameters on the dynamic characteristics of hydro-viscous flexible drive.

Details

Industrial Lubrication and Tribology, vol. 73 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

Access Restricted. View access options
Article
Publication date: 9 April 2018

Fangwei Xie, Jie Zhu, Jianzhong Cui, Xudong Zheng, Xinjian Guo, Yun Wang and Ramesh K. Agarwal

The purpose of this paper is to study the dynamic transmission of the oil film in soft start process of hydro-viscous drive (HVD) between the friction pairs with consideration of…

152

Abstract

Purpose

The purpose of this paper is to study the dynamic transmission of the oil film in soft start process of hydro-viscous drive (HVD) between the friction pairs with consideration of surface roughness, and obtain the distribution law of temperature, velocity, pressure, shear stress and viscous torque of the oil film.

Design/methodology/approach

The revised soft-start models of HVD were derived and calculated, including average Reynolds equation, asperity contact model, load force model and total torque model. Meanwhile, a 2D model of the oil film between friction pair was built and solved numerically using computational fluid dynamics (CFD) technique in FLUENT.

Findings

The results show that the maximum temperature gradually reduces from the intermediate range (z = 0.5 h) to the inner side of the friction pair along the direction of oil film thickness. As the soft-start process continues, pressure gradient along the direction of the oil film thickness gradually changes to zero. In addition, tangential velocity increases and yet radial velocity decreases with the increase of the radius.

Originality/value

In this paper, it was found that the viscous torque calculated by the numerical method is smaller than that by the CFD model, but their overall trend is almost the same. This also demonstrates the effectiveness of the numerical simulation.

Details

Industrial Lubrication and Tribology, vol. 70 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

Access Restricted. View access options
Article
Publication date: 5 February 2018

Hongtuo Liu, Fangwei Xie, Kai Zhang, Xinxing Zhang, Jin Zhang, Cuntang Wang and Hao Li

The shock absorber is an important component of vehicle suspension that attenuates the vehicle vibration. Its running state directly affects the performance of the vehicle…

246

Abstract

Purpose

The shock absorber is an important component of vehicle suspension that attenuates the vehicle vibration. Its running state directly affects the performance of the vehicle suspension. The purpose of this paper is to quantitatively study the relationship between damping characteristics and air chamber and oil properties in single-tube pneumatic shock absorber.

Design/methodology/approach

Combined with the principle of fluid dynamics and hydraulic transmission technology, the rebound stroke and compression stroke mathematical models, and damping characteristics simulation model are established to investigate the effect of the air chamber and oil property on damping characteristics.

Findings

Research results show that the initial pressure of the air chamber is the key parameter which influences the damping characteristics of the shock absorber. The change of the initial pressure has more impact on damping force, and less impact on the speed characteristic; the initial volume of the air chamber almost has no effect on the damping characteristics. The density and viscosity of the oil have certain influence on the damping characteristics. Therefore, selecting suitable damping oil is very important.

Originality/value

Using Matlab/Simulink software to build simulation models, its results are very accurate. The conclusions can provide a theoretical reference for the structure design of a single-tube pneumatic shock absorber.

Details

International Journal of Structural Integrity, vol. 9 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

Access Restricted. View access options
Article
Publication date: 22 July 2019

Qi Sun, Fangwei Xie, Kuaidi Wan, Xinjian Guo, Jie Zhu, Van Xo Nguyen and Yun Wang

The purpose of this paper is to study the influences of the oil film thickness between the friction pairs, the rotational speed of the active and passive friction disks and the…

103

Abstract

Purpose

The purpose of this paper is to study the influences of the oil film thickness between the friction pairs, the rotational speed of the active and passive friction disks and the inlet pressure of the lubricant on the transmission efficiency.

Design/methodology/approach

A mathematical model of transmission efficiency was established, and the efficiency of transmission was studied by means of numerical analysis.

Findings

The results demonstrate that the transmission efficiency decreases with the thickness of the oil film increases. When the thickness of oil film d = 0.1 mm, the relationship between transmission efficiency and transmission ratio is linear, that is, with the transmission ratio increases, the transmission efficiency also increases which does not change with the inlet pressure changes. However, when d = 0.1 mm, their relationship is non-linear; the efficiency increases first and then decreases as the transmission ratio increases, but decreases as the inlet pressure increases.

Originality/value

The authors obtained a rule is that increasing the rotational speed and reducing the inlet pressure of the lubricating oil can improve the transmission efficiency. This study can provide a theoretical basis for power transmission designing of hydro-viscous clutch.

Details

Industrial Lubrication and Tribology, vol. 71 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

1 – 10 of 23
Per page
102050