• Title/Summary/Keyword: Dimensionless Variables

Search Result 97, Processing Time 0.022 seconds

Modal Analysis Employing In-plane Strain of Cantilever Plates Undergoing Translational Acceleration (병진 가속을 받는 외팔 평판의 면내 변형율을 이용한 진동 해석)

  • Lim, Hong-Seok;Yoo, Hong-Hee
    • Proceedings of the KSME Conference
    • /
    • 2004.11a
    • /
    • pp.667-672
    • /
    • 2004
  • A modeling method for the modal analysis of cantilever plates undergoing in-plane translational acceleration is presented in this paper. Cartesian deformation variables are employed to derive the equations of motion and the resulting equations are transformed into dimensionless forms. To obtain the modal equation from the equations of motion, the in-plane equilibrium strain measures are substituted into the strain energy expression based on Von Karman strain measures. The effects of two dimensionless parameters (related to acceleration and aspect ratio) on the modal characteristics of accelerated plates are investigated through numerical studies.

  • PDF

Vibration Analysis of Rotating Cantilever Plates with a Concentrated Mass (집중 질량을 가진 회전하는 외팔 평판의 진동 해석)

  • 양정식;유홍희
    • Journal of KSNVE
    • /
    • v.8 no.6
    • /
    • pp.1130-1136
    • /
    • 1998
  • A modelling method for the vibration analysis of rotating cantilever plates with a concentrated mass is presented. The equations of motion for the rotating plates with a concentrated mass located in an arbitrary position are derived and transformed into a dimensionless form. For the mathematical modelling of the concentrated mass. a mass density Dirac delta function is used. The effects of concentrated mass and its location. angular speed. plate aspect ratio. and hub radius of the rotating plate on the natural frequencies are studied. Particularly. mode shape variations due to some parameter variations are investigated.

  • PDF

Vibration Analysis of A Rotating Cantilever Blade with Multiple Concentrated Masses with an Elastically Restrained Root (다중 집중질량효과에 의한 탄성 회전 블레이드의 진동해석)

  • Yun Kyung-Jae
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.7 no.4 s.19
    • /
    • pp.114-124
    • /
    • 2004
  • In this paper, we have proposed a novel method which can analysis a rotating elastically restrained blade with concentrated masses located in an arbitrary position. 1:he equations of motion are derived and transformed into a dimensionless form to investigate general phenomena. For the modeling of the multi-concentrated masses, the Dirac delta function is used for the mass density function. Simulation results show that the vibration characteristics of elastic restrained blade of according to dimensionless variables for example, multiple masses magnitude and mass location ratio. This method can be applied to an practical rotating blade system required to more accurate results.

Modal Analysis Employing In-plane Strain of Cantilever Plates Undergoing Translational Acceleration (병진 가속을 받는 외팔 평판의 면내 변형률을 이용한 진동 해석)

  • Yoo Hong Hee;Lim Hong Seok
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.29 no.6 s.237
    • /
    • pp.889-894
    • /
    • 2005
  • A modeling method for the modal analysis of cantilever plates undergoing in-plane translational acceleration is presented in this paper. Cartesian deformation variables are employed to derive the equations of motion and the resulting equations are transformed into dimensionless forms. To obtain the modal equation from the equations of motion, the in-plane equilibrium strain measures are substituted into the strain energy expression based on Von Karman strain measures. The effects of two dimensionless parameters (related to acceleration and aspect ratio) on the modal characteristics of accelerated plates are investigated through numerical studies.

A FE-based Model for Predicting Roll Force in a Vertical Rolling Process (수직압연에 대한 압하력 예측 모델)

  • Yun, D.J.;Kim, Y.K.;Hwang, S.M.
    • Transactions of Materials Processing
    • /
    • v.20 no.8
    • /
    • pp.548-554
    • /
    • 2011
  • A Finite Element (FE)-based model is proposed for predicting the roll force in an edger. The model is developed on the basis of the hypothetical mode of rolling and the least-squares regression analysis from the result of the FE approach. This model reflects the effect of process variables affected by the roll force, and has three dimensionless parameters, I.e., shape factor, reduction ratio and width-to-thickness ratio. The model prediction compared satisfactorily with experiment observations.

Performance Analysis of A Modified Asymmetric Rectangular Fin

  • Kang, Hyung Suk
    • Journal of the Korean Society for Industrial and Applied Mathematics
    • /
    • v.6 no.2
    • /
    • pp.109-120
    • /
    • 2002
  • The dimensionless heat loss from a modified asymmetric rectangular fin is investigated as a function of the fin top and tip Biot numbers using the two-dimensional separation of variables method. A rectangular fin is modified by attaching the wing on the top side of the fin. Fin effectiveness and efficiency with the variation of the location of the wing and the width of the wing are presented. The relationship between top surface Biot number and bottom surface Biot number as well as the relationship between the dimensionless wing height and the location of the wing for equal amount of heat loss is also discussed.

  • PDF

Effect of Vibration on Natural Convective Heat Transfer around a Spherical Body (구형물체 주위의 자연대류 열전달에 대한 진동효과)

  • Pak Hi-Yong;Cho Seung-Hwan
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
    • /
    • v.7 no.3
    • /
    • pp.151-159
    • /
    • 1978
  • A heat transfer model for the case of simultaneous vibration of both the heated surface and its surrounding medium is constructed and the dimensional analysis is applied to this model in order to and the governing dimensionless Parameters in which the vibration effects the heat transfer. In the second Part of this study, an experimental investigation of the effect of vibration on natural convective heal transfer from spheres has been performed for the case of the external oscillatory motion being imposed on the heated surface which is immersed in an otherwise undisturbed air, The ranges of the experimental variables were: temperature difference 10 to $120^{\circ}C$; vibration frequency 10 to 120Hz; displacement amplitude 1.3 to 12.5mm. Three different diameter aluminum were used as the experimental models. Improvements in heat transfer due to vibration were observed, with the maximum increase being 330 Percent. A dimensionless correlation describing the measured heat transfer data is given.

  • PDF

Ultimate lateral capacity of two dimensional plane strain rectangular pile in clay

  • Keawsawasvong, Suraparb;Ukritchon, Boonchai
    • Geomechanics and Engineering
    • /
    • v.11 no.2
    • /
    • pp.235-252
    • /
    • 2016
  • This paper presents a new numerical solution of the ultimate lateral capacity of rectangular piles in clay. The two-dimensional plane strain finite element was employed to determine the limit load of this problem. A rectangular pile is subjected to purely lateral loading along either its major or minor axes. Complete parametric studies were performed for two dimensionless variables including: (1) the aspect ratios of rectangular piles were studied in the full range from plates to square piles loaded along either their major or minor axes; and (2) the adhesion factors between the soil-pile interface were studied in the complete range from smooth surfaces to rough surfaces. It was found that the dimensionless load factor of rectangular piles showed a highly non-linear function with the aspect ratio of piles and a slightly non-linear function with the adhesion factor at the soil-pile interface. In addition, the dimensionless load factor of rectangular piles loaded along the major axis was significantly higher than that loaded along the minor axis until it converged to the same value at square piles. The solutions of finite element analyses were verified with the finite element limit analysis for selected cases. The empirical equation of the dimensionless load factor of rectangular piles was also proposed based on the data of finite element analysis. Because of the plane strain condition of the top view section, results can be only applied to the full-flow failure mechanism around the pile for the prediction of limiting pressure at the deeper length of a very long pile with full tension interface that does not allow any separation at soil-pile interfaces.

Effects of Operating Variables on the Solid Circulation Rate in a Three-phase Circulating Fluidized Bed

  • Kim, Min Kon;Hong, Sung Kyu;Lim, Dae Ho;Yoo, Dong Jun;Kang, Yong
    • Korean Chemical Engineering Research
    • /
    • v.53 no.4
    • /
    • pp.440-444
    • /
    • 2015
  • Effects of operating variables on the solid circulation rate were investigated in a three-phase circulating fluidized bed, of which inside diameter was 0.102m and height was 3.5m, respectively. Gas velocity, primary and secondary liquid velocities, particle size and height of solid particles piled up in the solid recycle device were chosen as operating variables. The solid circulation rate increased with increasing primary and secondary liquid velocities and height of solid particles piled up in the solid recycle device, but decreased with increasing particle size. The value of solid circulation rate decreased only slightly with increasing gas velocity in the riser. The values of solid circulation rate were well correlated in terms of dimensionless groups within the experimental conditions.

Numerical Analysis of the Non-Isothermal Heat Transfer in Solids Conveying Zone of a Single Screw Extruder (단축압출기 고체수송부에서의 비등온 열전달 현상에 관한 수치 해석)

  • Ahn Young-Cheol
    • Polymer(Korea)
    • /
    • v.29 no.6
    • /
    • pp.549-556
    • /
    • 2005
  • Effects of the dimensionless variables on the heat transport phenomena in the extrusion process of a single screw extruder have been studied numerically. Based on the understanding of the solids conveying related to the geometrical structure and characteristics of the screw, the heat balance equation for the solids conveying zone was established and normalized. The finite volume method and power-law scheme were applied to derive a discretized equation and the equation was solved using the alternating direction iterative method with relaxation. Effects of the dimensionless parameters, Biot and Peclet numbers, that define the heat transfer characteristics of the solids conveying zone have been investigated with respect to the temperature of the feeding zone and the length of the solids conveying zone. As the Biot number is increased, the heat loss by cooling dominates to decrease the temperature of the barrel but it has little effects on the temperature of the solids bed and the length of the solids conveying zone. On the other hand, if the Peclet number is increased, the convection term dominates to decrease the temperature of the solids bed and it results in an increase in the length of the solids conveying zone.