Analysis of the Dimensionless Torque in Cone Drum False Twisting Mechanism

Lee, Choon-Gil,Kang, Tae-Jin The Korean Fiber Society 2003 Fibers and polymers Vol.4 No.4

An investigation of the dimensionless torque in the newly developed cone drum twister texturing mechanism is reported. The cone drum twister is one of the outer surface contacting friction-twisting devices in false-twist texturing. In this cone drum twister, a filament yam passes over the surface of the cone drum that rotates by the passing yarn without a special driving device. This research is composed of the theoretical analysis of the false twisting mechanism and the experimental analysis at room temperature. The equations have been derived which shows interrelationship of the conical angle of cone drum, the wrapping angle, the drag angle, and the yam helix angle. Theoretical values of dimensionless torque were calculated and were compared with the experimental results. It is shown that, as the conical angle and the projected wrapping angle increased, the dimensionless torque also increased. But the conical angle was reached to ${30.75}^{\circ}C$, the dimensionless torque decreased.

Free vibration of symmetric angle ply truncated conical shells under different boundary conditions using spline method

K.K.Viswanathan,Z. A. Aziz,Saira Javed,Y. Yaacob,Babuji Pullepu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.5

Free vibration of symmetric angle-ply laminated truncated conical shell is analyzed to determine the effects of frequency parameterand angular frequencies under different boundary condition, ply angles, different material properties and other parameters. The governingequations of motion for truncated conical shell are obtained in terms of displacement functions. The displacement functions are approximatedby cubic and quintic splines resulting into a generalized eigenvalue problem. The parametric studies have been made and discussed.

자전거 프레임용 원추형 복합재 튜브의 굽힘 거동 분석

황상균 ( Sang-kyun Hwang ),이정우 ( Jung-woo Lee ),황희윤 ( Hui-yun Hwang ) 한국복합재료학회 2016 Composites research Vol.29 No.6

원추형 복합재 튜브는 우주 항공, 비행체, 잠수함 등 큰 구조물뿐만 아니라 자전거 프레임, 낚시대, 골프채 등 레저용품에도 적용이 되면서 정적-동적 거동에서의 기계적 물성 예측의 중요한 연구 분야로 대두되고 있다. 일반적으로 원추형 복합재 튜브의 기계적 물성 예측은 진동, 굽힘, 좌굴에 관하여 많은 연구가 진행되었지만, 복합재료의 섬유 배향 각이 일정하다고 가정하고 기계적 거동을 분석한 것이 대부분이기 때문에 섬유 배향 각이 원추형 복합재 튜브 구조물의 기계적 물성에 어떠한 영향을 미치는지에 대한 연구가 필요하다. 이에 본 연구에서는 섬유 배향 각을 고려한 원추형 복합재료 튜브의 정적 거동에 따른 기계적 물성을 예측하기 위해 수식을 도출하고, 자전거 프레임에 적용하기 위한 다양한 설계 파라메터의 영향을 고찰하였다. Mechanical properties of static and dynamic behavior became important since the use of conical composite tubes in large structures such as aerospace, planes, and submarines as well as leisure goods such as bicycle frames, fishing rods, and golf shafts. In the past, the mechanical property prediction model for static behavior was studied using vibration, bending, and buckling. But there is a need to study how fiber orientation error affects mechanical properties of conical composite structure because the model assumes constant fiber orientation angle. The purpose of this study is to derive an equation that can predict the static behavior of conical composite tube for bicycle frames by considering fiber orientation error with respect to various design parameters.

Free vibration of symmetric angle-ply layered conical shell frusta of variable thickness under shear deformation theory

K.K.Viswanathan,Saira Javed,Zainal Abdul Aziz 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.45 No.2

Free vibration of symmetric angle-ply layered conical shell frusta of variable thickness is analyzed under shear deformation theory with different boundary conditions by applying collocation with spline approximation. Linear and exponential variation in thickness of layers are assumed in axial direction. Displacements and rotational functions are approximated by Bickley-type splines of order three and obtained a generalized eigenvalue problem. This problem is solved numerically for an eigenfrequency parameter and an associated eigenvector of spline coefficients. The vibration of three and five–layered conical shells, made up of two different type of materials are considered. Parametric studies are made for analysing the frequencies of the shell with respect to the coefficients of thickness variations, length-to-radius ratio, length-to-thickness ratio and ply angles with different combination of the materials. The results are compared with the available data and new results are presented in terms of tables and graphs.

Free vibration of symmetric angle-ply layered conical shell frusta of variable thickness under shear deformation theory

Viswanathan, K.K.,Javed, Saira,Aziz, Zainal Abdul Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.45 No.2

Free vibration of symmetric angle-ply layered conical shell frusta of variable thickness is analyzed under shear deformation theory with different boundary conditions by applying collocation with spline approximation. Linear and exponential variation in thickness of layers are assumed in axial direction. Displacements and rotational functions are approximated by Bickley-type splines of order three and obtained a generalized eigenvalue problem. This problem is solved numerically for an eigenfrequency parameter and an associated eigenvector of spline coefficients. The vibration of three and five-layered conical shells, made up of two different type of materials are considered. Parametric studies are made for analysing the frequencies of the shell with respect to the coefficients of thickness variations, length-to-radius ratio, length-to-thickness ratio and ply angles with different combination of the materials. The results are compared with the available data and new results are presented in terms of tables and graphs.

원뿔형 오리피스 경사각이 유동 형태에 미치는 영향에 관한 수치적 연구

문시윤(S.Y. Moon) 한국전산유체공학회 2020 한국전산유체공학회지 Vol.25 No.1

Flow through the orifice can result in flow separation, reattachment, and recirculation. Cavitation, which occurs together with a sudden drop in pressure, can cause fluid-induced vibrations and noise, along with friction in the inner wall of the pipe. Many pieces of research have been conducted on these issues, and various methods have been proposed to solve the problems. Conical-shaped restriction orifices have been proposed and used in some applications as a way to solve the related issues, but the number of published studies on the flow characteristics through conical-shaped orifices is very small compared to flat orifices. In this study, the characteristics of conical orifice flow and the effect of conical orifice cone angle on the fluid behavior using single-phase flow were investigated by using the commercial computational fluid dynamics software ANSYS fluent 18.0.

Design of the Brake Device Using the Axial Crushing of Truncated Cone Type Cylinder

Jichul KIM,Woo Jeon SHIM 한국트라이볼로지학회 2002 한국트라이볼로지학회 학술대회 Vol.2002 No.10

A brake device lor the high-speed impacting object is designed using an axial crushing of thin-walled metal cylinder. Thickness of the cylinder is increased smoothly from the impacting end to the fixed end, resulting in the truncated cone shape. Truncated cone shape ensures that plastic hinges are formed sequentially from impacting end. This increases the reliability of brake device working. Computational and real experiments were performed to verity the effects of conical angle. Results indicate that undesirable sudden rise of crushing load can be prevented by applying appropriate conical angle.

Modal Analysis of Conical Shell Filled with Fluid

Myung Jo Jhung,Jong Chull Jo,Kyeong Hoon Jeong 대한기계학회 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.11

As a basic study on the fluid-structure interaction of the shell structure, a theoretical formulation has been suggested on the free vibration of a thin-walled conical frustum shell filled with an ideal fluid, where the shell is assumed to be fixed at both ends. The motion of fluid coupled with the shell is determined by means of the velocity potential flow theory. In order to calculate the normalized natural frequencies that represent the fluid effect on a fluid-coupled system, finite element analyses for a fluid-filled conical frustum shell are carried out. Also, the effect of apex angle on the frequencies is investigated.

Modal Analysis of Conical Shell Filled with Fluid

Jhung, Myung-Jo,Jo, Jong-Chull,Jeong, Kyeong-Hoon The Korean Society of Mechanical Engineers 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.11

As a basic study on the fluid-structure interaction of the shell structure, a theoretical formulation has been suggested on the free vibration of a thin-walled conical frustum shell filled with an ideal fluid, where the shell is assumed to be fixed at both ends. The motion of fluid coupled with the shell is determined by means of the velocity potential flow theory. In order to calculate the normalized natural frequencies that represent the fluid effect on a fluid-coupled system, finite element analyses for a fluid-filled conical frustum shell are carried out. Also, the effect of apex angle on the frequencies is investigated.

Optimizing conical nozzle of venturi ejector in ejector loop reactor using computational fluid dynamics

Enle Xu,Xiaofeng Jiang,Long Ding 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.11

The structure of a conical nozzle is critical to the gas induction of a venturi ejector. In this work, the effect of nozzle structure on the gas induction was investigated by means of multiphase CFD and validating experiments. Under different structures, the maximal gas induction was obtained through analyzing the nozzle outlet velocity (NOV), nozzle inlet velocity (NIV), as well as nozzle shrinking angle (NSA). The simulated inlet pressure is positively proportional to inlet flow rate, which is in good agreement with experimental results. The simulated results reveal that the inlet pressure and gas induction increase with the increasing NOV. Considering the operational characteristics of centrifugal pump, the recommended NOV is about 21.8m/s. NIV and NSA show little impact on gas induction and inlet pressure. Based on the pipeline energy consumption, the recommended NIV is the same as the outlet velocity of centrifugal pump. The recommended NSA is about 20o to obtain the maximal gas induction.