Three-dimensional simulation and experimental investigation of three-dimensional printed guiding devices on lattice-apron compact spinning

2020 ◽  
pp. 004051752098258
Author(s):  
Malik YH Saty ◽  
Nicholus Tayari Akankwasa ◽  
Jun Wang
Keyword(s):  
Experimental Investigation ◽  
Air Flow ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Yarn Properties ◽  
3D Printed ◽  
Dimensional Simulation ◽  
Compact Spinning ◽  
Set Up

The compact spinning system with a lattice apron utilizes air-flow dynamics to condense fibers in a bunch and enhance the yarn properties. One of the main challenges with this method is the lack of a comprehensive understanding of the air-flow field's effect in the condensing zone. This work presents a numerical and experimental investigation of the effects of three-dimensional (3D) printed guiding devices on the air-flow characteristics and yarn properties. Firstly, the 3D numerical model of the compact spinning system was set up based on the compact spinning machine geometrical dimensions. Secondly, different 3D prototypes were developed, simulated, and analyzed using computational fluid dynamics based on ANSYS software. The prototypes (A-type, B-type, and C-type), selected according to the simulation results, were then 3D printed to enable further experimental investigation. Air-flow analysis results in the air-suction flume area exhibiting a very high negative pressure, and the centerline zone was characterized by high velocity. Experimental results revealed that the three yarns spun with guiding devices had better strength, hairiness, and evenness than those spun without a guiding device. The model developed can be further improved and utilized for commercial purposes and is anticipated to improve compact spun yarn properties significantly.

Numerical and experimental approach towards an energy-efficient compact spinning system

2021 ◽  
pp. 004051752110432
Author(s):  
Malik YH Saty ◽  
Nicholus Tayari Akankwasa ◽  
Jun Wang
Keyword(s):  
Experimental Investigation ◽  
Negative Pressure ◽  
Three Dimensional ◽  
High Energy ◽  
Yarn Properties ◽  
3D Printed ◽  
Yarn Production ◽  
Compact Spinning ◽  
Set Up ◽  
Geometrical Dimensions

Compact spinning with a lattice apron has recently become a very attractive approach for pneumatic compact yarn production spinning systems. One of the main challenges with use of this method is the high negative pressure that leads to high energy consumption. In response to this challenge, we present a numerical and experimental investigation of the effects of a three-dimensional (3D) printed guiding device on the airflow characteristics and yarn properties. Initially, the 3D numerical model of the compact spinning system was set up based on the real geometrical dimensions. Secondly, the 3D prototype was developed, simulated, and analyzed using Solidworks and Ansys. Ultimately, the design, which exhibited low negative pressure along the model domain, was adopted and then 3D printed to enable further experimental investigation. Airflow analysis results illustrated that when using the guiding device with low negative pressure, the active area of negative pressure was increased. This was due to the existence and the special design of the guiding device that prevented the decrease of the negative pressure with atmospheric pressure. This increased the transverse condensing force, which was beneficial for twisting the free-end fiber around the fiber bundle. Experimental results revealed that the three yarns spun with the guiding device achieved significant energy saving when the guiding device was used. Moreover, these yarns spun with the guiding device had better strength, hairiness, and evenness than those spun without a guiding device. The model developed can be further improved and utilized for commercial purposes, as it significantly reduces energy costs while improving yarn properties.

scholarly journals THREE DIMENSIONAL SIMULATION OF OIL FLOW CHARACTERISTICS IN LUBRICATION SYSTEM OF ROTARY TILLAGE ENGINE

2021 ◽  
pp. 163-172
Author(s):  
Junxiang Gao ◽  
Xiaoliang Gao ◽  
Wei Zou
Keyword(s):  
Pressure Drop ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Lubricating Oil ◽  
Flow Index ◽  
Lubrication System ◽  
Pump Rotor ◽  
Oil Pump ◽  
Oil Flow ◽  
Dimensional Simulation

Taking the lubrication system of rotary tillage engine as the research object, this paper makes a three-dimensional simulation study on the oil flow characteristics in the lubricating oil passage. The oil supply of the oil pump shall be greater than the circulating oil required by the lubrication system to ensure the lubrication of the rotary cultivator. Lubrication system is an important part to ensure the reliability and durability of rotary cultivator. The key component to achieve its performance is the oil pump. The geometric model of lubricating oil flow field in rotary tiller lubrication system is established by using FLUENT software. The results show that the pressure drop in the lubricating oil passage of the main bearing is the largest under the same working conditions. In the oil passage of the cylinder head, the pressure drop of the front main oil passage is the largest and the oil discharge is the largest. Add 1.6mm oil pump rotor on the basis of the thickness of the original oil pump rotor, the oil flow at the connecting rod nozzle reaches the flow index of the original rotary cultivator, and there is no cylinder pulling phenomenon of the rotary cultivator.

Investigations on the Rotordynamic Characteristics of a Hole-Pattern Seal Using Transient CFD and Periodic Circular Orbit Model

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Xin Yan ◽  
Jun Li ◽  
Zhenping Feng
Keyword(s):  
Circular Orbit ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Numerical Approach ◽  
Deformation Method ◽  
Rotordynamic Coefficients ◽  
Forward Orbit ◽  
Reaction Forces ◽  
Orbit Model

Numerical investigations on the rotordynamic characteristics of a typical hole-pattern seal using transient three-dimensional Reynolds-averaged Navier–Stokes (RANS) solution and the periodic circular orbit model were conducted in this work. The unsteady solutions combined with mesh deformation method were utilized to solve the three-dimensional RANS equations and obtain the transient reaction forces on a typical hole-pattern seal rotor at five different excitation frequencies. The relation between the periodic reaction forces and frequency dependent rotordynamic coefficients of the hole-pattern seal was obtained by considering the rotor with a periodic circular orbit (including forward orbit and backward orbit) of the seal center. The rotordynamic coefficients of the hole-pattern seal were then solved based on the obtained unsteady reaction forces and presented numerical method. Compared with the experimental data, the predicted rotordynamic coefficients of the hole-pattern seal are more agreeable with the experiment than that of the ISO-temperature (ISOT) bulk flow analysis and numerical approach with one-direction-shaking model. Furthermore, the unsteady leakage flow characteristics in the hole-pattern seal were also illustrated and discussed in detail.

Three Dimensional Simulation of the Effect of Windcatcher’s Inlet Shape

2019 ◽  
Author(s):  
Peter Abdo ◽  
Rahil Taghipour ◽  
B. P. Huynh
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Indoor Environment ◽  
Natural Ventilation ◽  
Air Flow ◽  
Three Dimensional ◽  
Sectional Area ◽  
Cross Sectional ◽  
Dimensional Simulation ◽  
Convergent Inlet

Abstract Windcatcher has been used over centuries for providing natural ventilation using wind power, it is an effective passive method to provide healthy and comfortable indoor environment. The windcatcher’s function is based on the wind and on the stack effect resulting from temperature differences. Generally, it is difficult for wind to change its direction, and enter a room through usual openings, the windcatcher is designed to overcome such problems since they have vertical columns to help channel wind down to the inside of a building. The efficiency of a windcatcher is maximized by applying special forms of opening and exit. The openings depend on the windcatcher’s location and on its cross sectional area and shape such as square, rectangular, hexagonal or circular. In this study the effect of the inlet design is investigated to achieve better air flow and increase the efficiency of windcatchers. To achieve this, CFD (computational fluid dynamics) tool is used to simulate the air flow in a three dimensional room fitted with a windcatcher based on the different inlet designs. The divergent inlet has captured the highest air flow with a difference of approximately 3% compared to the uniform inlet and 5% difference compared to the bulging-convergent inlet.

Three-Dimensional Simulation of Turbulent Rectangular and Square Impinging Jet Flows

2004 ◽  
Author(s):  
Qingguang Chen ◽  
Zhong Xu ◽  
Yulin Wu ◽  
Yongjian Zhang
Keyword(s):  
Recirculation Zone ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Adverse Pressure Gradient ◽  
Impinging Jet ◽  
Boundary Layer Separation ◽  
Streamwise Velocity ◽  
Impinging Jets ◽  
Jet Flows ◽  
Dimensional Simulation

Flow characteristics of turbulent impinging jets issuing, respectively, from a rectangular and a square nozzles have been investigated numerically through the solution of three-dimensional Navier-Strokes equations in steady state. Two geometries with two nozzle-to-plate spacings of four and eight times of hydraulic diameters of the jet pipes, and two Reynolds numbers of 20000 and 30000 have been considered with fully developed inlet boundary conditions. An RNG based k–ε turbulence model and a deferred correction QUICK scheme in conjunction with the wall function method have been applied to the prediction of the flow fields within semi-confined spaces. A common feature revealed by the computational results is the presence of a toroidal recirculation zone around the jet. An adverse pressure gradient is found at the impingement surface downstream the stagnation point. Boundary layer separation will occur if the gradient is strong enough, and the separation manifests itself as a secondary recirculation zone at the surface. In addition, three-dimensional simulations reveal the existence of two and four pronounced streamwise velocity off-center peaks at the cross-planes near to the impingement plate, respectively, in the rectangular and square impinging jet flows. These peaks are found forming at the horizontal planes where the wall jets start forming accompanied by two or four pairs of counter-rotating vortex rings. It is believed that the formation of the off-center velocity peaks is due to the vorticity diffusion along the wall jet as the jet impinges on the target plate.

CFD Analysis of Composite Axial Water Turbine

2010 ◽  
Author(s):  
Jifeng Wang ◽  
Norbert Mu¨ller
Keyword(s):  
Design Method ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Cfd Analysis ◽  
Computational Investigation ◽  
Rotating Speed ◽  
Fundamental Understanding ◽  
Water Turbine ◽  
Water Turbines

This paper presents computational investigation of the flow in composite material axial water turbines using Finite Volume based commercial CFD package namely Fluent. Based on three dimensional numerical flow analysis and fluid-structure interaction, the flow characteristics of water turbines including nozzle, impeller and diffuser are predicted. Two particulare cases are studied and compared. The extract power of water turbine in different rotating speed and water inlet velocity are analyzed. The calculated results will provide a fundamental understanding of the impeller as water turbine, and this design method is used to shorten the design period and improve the water turbine’s performance.

Experimental Investigation of the Flow Field of a Ceiling Fan

Volume 3 ◽  
2004 ◽  
Author(s):  
Ankur Jain ◽  
Rochan Raj Upadhyay ◽  
Samarth Chandra ◽  
Manish Saini ◽  
Sunil Kale
Keyword(s):  
Experimental Investigation ◽  
Energy Consumption ◽  
Flow Field ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Tip Vortex ◽  
Optimal Designs ◽  
Tropical Regions ◽  
Fundamental Understanding ◽  
Blade Tip

A ceiling fan is the predominating comfort provider in tropical regions worldwide. It consists of an assembly of an electric motor with 3–4 blades suspended from the ceiling of a room. Despite its simplicity and widespread use, the flow induced by a ceiling fan in a closed room has not been investigated, and sub-optimal designs are in wide use. There is vast potential for energy conservation and improved comfort by developing optimized fan designs. This work develops a fundamental understanding of the flow characteristics of a ceiling operating inside a closed room. Using smoke from thick incense sticks, the flow field created by the ceiling fan is visualized. In most regions, the flow is periodic and three-dimensional. Vortices are seen to be attached to the blade tip and hub, which reduces downward flow and increases energy consumption. Only the middle 75% of blade actually pushes the air downwards, and the comfort region is limited to a cylinder directly under the blades; velocities in this region were measured with a vane anemometer. Winglets and spikes attached to the blade tip disrupted the tip vortex, and increased downflow by about 13% without any increase in power consumption.

Helium Turboexpander for Cryogenic Refrigeration and Liquefaction Cycles: Transient Analysis of Rotor–Stator Interaction

2016 ◽  
Author(s):  
Ashish Alex Sam ◽  
Parthasarathi Ghosh
Keyword(s):  
Turbulent Flows ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Space Length ◽  
Turbine Wheel ◽  
Mechanical Constraints ◽  
Computational Fluid Dynamics Analysis ◽  
Flow Mechanisms ◽  
Rotor Stator Interaction

Computational fluid dynamics analysis of the complex flows in a cryogenic turboexpander is essential for any improvement in its performance. This includes a detailed analysis of the unsteady turbulent flows imparted mainly by the rotor stator interactions. The flow unsteadiness due to rotor stator interaction is caused by the relative motion between the stationary and rotating component, interaction of the turbine wheel blades with the wakes and vortices generated by the upstream blades and at trailing edges. In order to minimize the loss generation due to this unsteadiness, the vaneless space length at the nozzle-turbine wheel interface and the length of the straightening portion at the turbine wheel-diffuser interface should be optimised considering the mechanical constraints. In this paper three dimensional unsteady viscous flow analysis of a helium cryogenic turboexpander was carried out using Ansys CFX to investigate the origin and flow mechanisms that cause these unsteady phenomena. The analysis has been done for three different lengths of straightening duct at the turbine wheel diffuser interface. The performance parameters from the computational results were compared and analysed to understand the flow characteristics in each case.

A High-Order LES Turbulent Model to Study Unsteady Flow Characteristics in a High Pressure Turbine Cascade

2008 ◽  
Author(s):  
Tomohiko Jimbo ◽  
Debasish Biswas ◽  
Yasuyuki Yokono ◽  
Yoshiki Niizeki
Keyword(s):  
Physical Process ◽  
Pressure Loss ◽  
Flow Behavior ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Measured Data ◽  
High Order ◽  
Turbulent Model ◽  
Loss Mechanism

In this work, unsteady viscous flow analysis around turbine blade cascade using a High-Order LES turbulent model is carried out to investigate basic physical process involved in the pressure loss mechanism. This numerical analysis is assessed to the wind tunnel cascade test. Basically, all the physical phenomena occurring in nature are the effect of some cause, and the effect can somehow be measured. However, to understand the cause, detail information regarding the visualization of the phenomena, which are difficult to measure, are necessary. Therefore, in our work, firstly the computed results are compared with the measured data, which are the final outcome of the cause (of the phenomena under investigation), to verify whether our physics-based model could qualitatively predict the measured facts or not. It was found that the present model could well predict measured data. Therefore, the rest of the computed information, which were difficult to measure, were used to visualize the overall flow behavior for acquiring some knowledge of the physical process associated with the pressure loss mechanism. Our study led to an understanding that the interaction of the vortex generated on the suction and pressure surface of the blade and the secondary vortex generated on the end-wall, downstream the trailing edge resulted in the formation of a large vortex structure in this region. This unsteady three-dimensional flow characteristic is expected to play an important role in the pressure loss mechanism.

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