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Yuetzu Yang - One of the best experts on this subject based on the ideXlab platform.

  • Unsteady unidirectional Flow of a Voigt fluid in the circular duct with different prescribed Volume Flow rate conditions
    Heat and Mass Transfer, 2004
    Co-Authors: C. I. Chen, C. K. Chen, Yuetzu Yang
    Abstract:

    In the present study, the velocity profile and pressure gradient of the unsteady state unidirectional Flow of a Voigt fluid in a circular duct with different prescribed Volume Flow rate are investigated. The Flow motion in the duct is induced by a prescribed Inlet Volume Flow rate which varies with time. Based on the Flow conditions prescribed, two basic Flow situations are solved; these are a suddenly started, and a constant accelerated, Flow respectively. These two results are then applied to a practical case that is a trapezoidal motion which contains three phases of piston motion, the constant acceleration from the rest to a fixed velocity, then maintaining at this velocity, following with the constant deceleration to a stop. In addition, oscillatory Flow is also considered.

  • unsteady unidirectional Flow of bingham fluid between parallel plates with different given Volume Flow rate conditions
    Applied Mathematical Modelling, 2004
    Co-Authors: Chuni Chen, Chaokuang Chen, Yuetzu Yang
    Abstract:

    Abstract In this paper, the velocity profile and pressure gradient of the unsteady state unidirectional Flow of Bingham fluid between parallel plates are solved by the Laplace transform method. The Flow motion between the plates is induced by a prescribed arbitrary Inlet Volume Flow rate which varies with time. Based on the Flow conditions described, two basic Flow situations are solved; these are a suddenly started, and a constant acceleration, Flow respectively. These two results are then applied to a practical case that is a trapezoidal piston motion which contains three phases of piston motion, the constant acceleration from the rest to a fixed velocity, then keeping at this velocity, following with the constant deceleration to a stop. In addition, oscillatory Flow is also considered. The result indicates when the yield stress τ 0 is equal to zero, the solution to the problem reduces to that of a Newtonian fluid.

  • Unsteady unidirectional Flow of an Oldroyd-B fluid in a circular duct with different given Volume Flow rate conditions
    Heat and Mass Transfer, 2004
    Co-Authors: C. I. Chen, C. K. Chen, Yuetzu Yang
    Abstract:

    In this paper, the velocity profile and pressure gradient of the unsteady state unidirectional Flow of an Oldroyd-B fluid in a circular duct are considered. The Flow motion in the duct is induced by a given but arbitrary Inlet Volume Flow rate which varies with time. Based on the Flow conditions described, two basic Flow situations are solved, which are a suddenly started, and a constant acceleration, Flow respectively. These two results are applied to a practical case that is a trapezoidal piston motion which contains three phases of piston motion, the constant acceleration from the rest to a fixed velocity, then keeping at this velocity, following with the constant deceleration to a stop. In addition, oscillatory Flow is also considered.

  • unsteady unidirectional Flow of second grade fluid between the parallel plates with different given Volume Flow rate conditions
    Applied Mathematics and Computation, 2003
    Co-Authors: Chuni Chen, Chaokuang Chen, Yuetzu Yang
    Abstract:

    In this paper, the velocity profile and pressure gradient of the unsteady state unidirectional Flow of second grade fluids between the parallel plates are considered. The Flow motion in the plates is induced by a given but arbitrary Inlet Volume Flow rate which varies with time. Based on the Flow conditions described, two basic Flow situations are solved, which are a sudden started and a constant acceleration Flow, respectively. Then we apply these two results to a practical case that is a trapezoidal piston motion which contains three phases of piston motion, the constant acceleration from the rest to a fixed velocity, then keeping at this velocity, following with the constant deceleration to a stop. In addition, the oscillatory Flow is also considered.

Chuni Chen - One of the best experts on this subject based on the ideXlab platform.

  • the effect of wall slip condition on the transient Flow of oldroyd b fluid under given Inlet Volume Flow rate variations
    Journal of The Chinese Society of Mechanical Engineers, 2012
    Co-Authors: Yinwei Lin, Chuni Chen
    Abstract:

    The research of microFlow pattern draws great attention from scientists. Its characteristic is the slip on the wall and it is frequently occurred in the real world engineering applications. In this study, the authors will re-explore previous study [Heat and Mass Transfer, vol. 40, pp. 203-209 (2004)] with Oldroyd-B fluid in the circular tube under the influence of wall slip condition. The velocity profile and pressure gradient in a microcircular tube are solved by Laplace transform method. As the velocity slip condition at the wall imposed, the boundary conditions should be modified. The Flow motion is induced by a prescribed arbitrary Inlet Volume Flow rate which was proposed by Das et. al. [ASME J. Appl. Mech., vol. 67, pp. 274-281 (2000)]. In this paper, two basic Flow situations are solved. These are a suddenly started and a constant acceleration Flow, respectively. The linear acceleration and oscillatory Flow are also considered.

  • analysis of unsteady Flow through a microtube with wall slip and given Inlet Volume Flow rate variations
    Journal of Applied Mechanics, 2008
    Co-Authors: Chuni Chen, Chaokuang Chen, Hengju Lin
    Abstract:

    This study examines the effects of rarefaction of an unsteady Flow through a microtube for a given but arbitrary Inlet Volume Flow rate. Four cases of Inlet Volume Flow rate proposed by Das and Arakeri (2000, ASME J. Appl. Mech., 67, pp. 274-281) are as follows: (1) trapezoidal piston motion, (2) constant acceleration, (3) impulsively started Flow, and (4) impulsively blocked fully developed Flow. During the analysis process, the Knudsen number (Kn) is used to represent the degree of rarefaction. The analytical results are presented graphically and compared to the results for a continuum under a no-slip condition. The effect of wall-slip became significant with the increasing degrees of rarefaction. The velocity in the boundary layer increased, whereas the velocity in the potential core of the microtube decreased, under the same condition. The influence of the rarefaction for the pressure gradient varied for the four cases.

  • unsteady unidirectional Flow of bingham fluid between parallel plates with different given Volume Flow rate conditions
    Applied Mathematical Modelling, 2004
    Co-Authors: Chuni Chen, Chaokuang Chen, Yuetzu Yang
    Abstract:

    Abstract In this paper, the velocity profile and pressure gradient of the unsteady state unidirectional Flow of Bingham fluid between parallel plates are solved by the Laplace transform method. The Flow motion between the plates is induced by a prescribed arbitrary Inlet Volume Flow rate which varies with time. Based on the Flow conditions described, two basic Flow situations are solved; these are a suddenly started, and a constant acceleration, Flow respectively. These two results are then applied to a practical case that is a trapezoidal piston motion which contains three phases of piston motion, the constant acceleration from the rest to a fixed velocity, then keeping at this velocity, following with the constant deceleration to a stop. In addition, oscillatory Flow is also considered. The result indicates when the yield stress τ 0 is equal to zero, the solution to the problem reduces to that of a Newtonian fluid.

  • unsteady unidirectional Flow of second grade fluid between the parallel plates with different given Volume Flow rate conditions
    Applied Mathematics and Computation, 2003
    Co-Authors: Chuni Chen, Chaokuang Chen, Yuetzu Yang
    Abstract:

    In this paper, the velocity profile and pressure gradient of the unsteady state unidirectional Flow of second grade fluids between the parallel plates are considered. The Flow motion in the plates is induced by a given but arbitrary Inlet Volume Flow rate which varies with time. Based on the Flow conditions described, two basic Flow situations are solved, which are a sudden started and a constant acceleration Flow, respectively. Then we apply these two results to a practical case that is a trapezoidal piston motion which contains three phases of piston motion, the constant acceleration from the rest to a fixed velocity, then keeping at this velocity, following with the constant deceleration to a stop. In addition, the oscillatory Flow is also considered.

Chaokuang Chen - One of the best experts on this subject based on the ideXlab platform.

  • analysis of unsteady Flow through a microtube with wall slip and given Inlet Volume Flow rate variations
    Journal of Applied Mechanics, 2008
    Co-Authors: Chuni Chen, Chaokuang Chen, Hengju Lin
    Abstract:

    This study examines the effects of rarefaction of an unsteady Flow through a microtube for a given but arbitrary Inlet Volume Flow rate. Four cases of Inlet Volume Flow rate proposed by Das and Arakeri (2000, ASME J. Appl. Mech., 67, pp. 274-281) are as follows: (1) trapezoidal piston motion, (2) constant acceleration, (3) impulsively started Flow, and (4) impulsively blocked fully developed Flow. During the analysis process, the Knudsen number (Kn) is used to represent the degree of rarefaction. The analytical results are presented graphically and compared to the results for a continuum under a no-slip condition. The effect of wall-slip became significant with the increasing degrees of rarefaction. The velocity in the boundary layer increased, whereas the velocity in the potential core of the microtube decreased, under the same condition. The influence of the rarefaction for the pressure gradient varied for the four cases.

  • unsteady unidirectional Flow of bingham fluid between parallel plates with different given Volume Flow rate conditions
    Applied Mathematical Modelling, 2004
    Co-Authors: Chuni Chen, Chaokuang Chen, Yuetzu Yang
    Abstract:

    Abstract In this paper, the velocity profile and pressure gradient of the unsteady state unidirectional Flow of Bingham fluid between parallel plates are solved by the Laplace transform method. The Flow motion between the plates is induced by a prescribed arbitrary Inlet Volume Flow rate which varies with time. Based on the Flow conditions described, two basic Flow situations are solved; these are a suddenly started, and a constant acceleration, Flow respectively. These two results are then applied to a practical case that is a trapezoidal piston motion which contains three phases of piston motion, the constant acceleration from the rest to a fixed velocity, then keeping at this velocity, following with the constant deceleration to a stop. In addition, oscillatory Flow is also considered. The result indicates when the yield stress τ 0 is equal to zero, the solution to the problem reduces to that of a Newtonian fluid.

  • unsteady unidirectional Flow of second grade fluid between the parallel plates with different given Volume Flow rate conditions
    Applied Mathematics and Computation, 2003
    Co-Authors: Chuni Chen, Chaokuang Chen, Yuetzu Yang
    Abstract:

    In this paper, the velocity profile and pressure gradient of the unsteady state unidirectional Flow of second grade fluids between the parallel plates are considered. The Flow motion in the plates is induced by a given but arbitrary Inlet Volume Flow rate which varies with time. Based on the Flow conditions described, two basic Flow situations are solved, which are a sudden started and a constant acceleration Flow, respectively. Then we apply these two results to a practical case that is a trapezoidal piston motion which contains three phases of piston motion, the constant acceleration from the rest to a fixed velocity, then keeping at this velocity, following with the constant deceleration to a stop. In addition, the oscillatory Flow is also considered.

C. I. Chen - One of the best experts on this subject based on the ideXlab platform.

  • exact solutions for the unsteady Flow of a burger s fluid in a duct induced by time dependent prescribed Volume Flow rate
    Heat and Mass Transfer, 2006
    Co-Authors: C. I. Chen, Tasawar Hayat, Jiann-lin Chen
    Abstract:

    In this investigation, some unsteady Flows in a circular duct have been studied. The fluid obeys viscoelastic non-Newtonian model with the Burgers’ constitutive equation and all fluid properties are constant. The Flows in a duct are due to the prescribed arbitrary time dependent Inlet Volume Flow rates. Four types of Flow situations are considered. The governing equations are first developed and then solved using Laplace transform technique. Results indicate the strong effect of Burgers’ fluid parameter on the velocity fields and pressure gradients.

  • Unsteady unidirectional Flow of a Voigt fluid in the circular duct with different prescribed Volume Flow rate conditions
    Heat and Mass Transfer, 2004
    Co-Authors: C. I. Chen, C. K. Chen, Yuetzu Yang
    Abstract:

    In the present study, the velocity profile and pressure gradient of the unsteady state unidirectional Flow of a Voigt fluid in a circular duct with different prescribed Volume Flow rate are investigated. The Flow motion in the duct is induced by a prescribed Inlet Volume Flow rate which varies with time. Based on the Flow conditions prescribed, two basic Flow situations are solved; these are a suddenly started, and a constant accelerated, Flow respectively. These two results are then applied to a practical case that is a trapezoidal motion which contains three phases of piston motion, the constant acceleration from the rest to a fixed velocity, then maintaining at this velocity, following with the constant deceleration to a stop. In addition, oscillatory Flow is also considered.

  • Unsteady unidirectional Flow of an Oldroyd-B fluid in a circular duct with different given Volume Flow rate conditions
    Heat and Mass Transfer, 2004
    Co-Authors: C. I. Chen, C. K. Chen, Yuetzu Yang
    Abstract:

    In this paper, the velocity profile and pressure gradient of the unsteady state unidirectional Flow of an Oldroyd-B fluid in a circular duct are considered. The Flow motion in the duct is induced by a given but arbitrary Inlet Volume Flow rate which varies with time. Based on the Flow conditions described, two basic Flow situations are solved, which are a suddenly started, and a constant acceleration, Flow respectively. These two results are applied to a practical case that is a trapezoidal piston motion which contains three phases of piston motion, the constant acceleration from the rest to a fixed velocity, then keeping at this velocity, following with the constant deceleration to a stop. In addition, oscillatory Flow is also considered.

Bonesi Marco - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of Flow dynamics in vessels with complex geometry using Doppler optical coherence tomography
    2008
    Co-Authors: Meglinski Igor, Bonesi Marco
    Abstract:

    The study of Flow dynamics in complex geometry vessels is highly important in many biomedical applications where the knowledge of the mechanic interactions between the moving fluid and the housing media plays a key role for the determination of the parameters of interest, including the effect of blood Flow on the possible rupture of atherosclerotic plaques. Doppler Optical Coherence Tomography (DOCT) is an optic, non-contact, non-invasive technique able to achieve detailed analysis of the Flow/vessel interactions, allowing simultaneously high resolution imaging of the morphology and composition of the vessel and of the Flow velocity distribution along the measured cross-section. DOCT system was developed to image high-resolution one-dimensional and multi-dimensional velocity distribution profiles of Newtonian and non-Newtonian fluids Flowing in vessels with complex geometry, including Y-shaped and T-shaped vessels, vessels with aneurism, bifurcated vessels with deployed stent and scaffolds. The phantoms were built to study the interaction of the Flow dynamics with different channel geometries and to map the related velocity profiles at several Inlet Volume Flow rates. Feasibility studies for quantitative observation of the turbulence of Flows arising within the complex geometry vessels are discussed. In addition, optical clearing of skin tissues has been utilized to achieve DOCT imaging of human blood vessels in vivo, at a depth up to 1.7 mm. Two-dimensional OCT images of complex Flow velocity profiles in blood vessel phantom and in vivo subcutaneous human skin tissues are presented. The effect of optical clearing on in vivo images is demonstrated and discussed. DOCT was also applied for imaging scaffold structures and for mapping Flow distributions within the scaffold.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

  • Characterization of Flow Dynamics in Vessels with Complex Geometry using Doppler Optical Coherence Tomography
    Cranfield University, 2008
    Co-Authors: Bonesi Marco
    Abstract:

    The study of Flow dynamics in complex geometry vessels is highly important in many biomedical applications where the knowledge of the mechanic interactions between the moving fluid and the housing media plays a key role for the determination of the parameters of interest, including the effect of blood Flow on the possible rupture of atherosclerotic plaques. Doppler Optical Coherence Tomography (DOCT) is an optic, non-contact, non-invasive technique able to achieve detailed analysis of the Flow/vessel interactions, allowing simultaneously high resolution imaging of the morphology and composition of the vessel and of the Flow velocity distribution along the measured cross-section. DOCT system was developed to image high-resolution one-dimensional and multi-dimensional velocity distribution profiles of Newtonian and non-Newtonian fluids Flowing in vessels with complex geometry, including Y-shaped and T-shaped vessels, vessels with aneurism, bifurcated vessels with deployed stent and scaffolds. The phantoms were built to study the interaction of the Flow dynamics with different channel geometries and to map the related velocity profiles at several Inlet Volume Flow rates. Feasibility studies for quantitative observation of the turbulence of Flows arising within the complex geometry vessels are discussed. In addition, optical clearing of skin tissues has been utilized to achieve DOCT imaging of human blood vessels in vivo, at a depth up to 1.7 mm. Two-dimensional OCT images of complex Flow velocity profiles in blood vessel phantom and in vivo subcutaneous human skin tissues are presented. The effect of optical clearing on in vivo images is demonstrated and discussed. DOCT was also applied for imaging scaffold structures and for mapping Flow distributions within the scaffold