Wakana Hiratsuka^a , Takashi Fukue^b,*, Hidemi Shirakawa^c, Katsuyuki Nakayama^d, Yasushi Koito^e

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-8, 2020, DOI:10.5098/hmt.15.16

Abstract This paper describes a possibility of heat transfer enhancement in a mm-scale flow channel by using a combination of some projections and pulsating flow. The objective of this research is to develop a novel heat exchanger for miniaturized productions such as high-density packaging electronic equipment by applying pulsating flow to enhance heat transfer while inhibiting an increase of pressure drop. In order to evaluate the possibility of applying pulsating flow to miniature water channels, a three-dimensional flow and heat transfer analysis was performed. Heat transfer performance of a combination of pulsating water flow and a projection was investigated. The mechanism… More >

Shintaro Hayakawa^a , Takashi Fukue^a,*,† , Yasuhiro Sugimoto^a , Wakana Hiratsuka^b , Hidemi Shirakawa^c , Yasushi Koito^d

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-9, 2022, DOI:10.5098/hmt.18.29

Abstract This paper describes the effects of a combination of rib and pulsating flow on heat transfer enhancement in an mm-scale model that simulates the narrow flow passages in cooling devices of downsized electronic equipment. This research aims to develop a novel water cooling device that increases heat transfer performance while inhibiting pumping power. Our recent study has reported that a combination of pulsating flow and rib could enhance heat transfer performance relative to the simple duct. In the present study, to verify the optimal rib height for improving heat transfer by pulsating flow, we evaluated the relationship between heat transfer… More >

Tin-Kan Hung^1,*, Ruei-Hung Kuo², Cheng-Hsien Chiang³

Molecular & Cellular Biomechanics, Vol.17, No.1, pp. 19-24, 2020, DOI:10.32604/mcb.2019.07817

Abstract Kinematic and dynamic characteristics of pulsating flow in a model of human aortic arch are obtained by a computational analysis. Three-dimensional flow processes are summarized by pressure distributions on the symmetric plane together with velocity and pressure contours on a few cross sections for systolic acceleration and deceleration. Without considering the effects of aortic tapering and the carotid arteries, the development of tubular boundary layer with centrifugal forces and pulsation are also analyzed for flow separation and backflow during systolic deceleration. More >

Tin-Kan Hung^1,*, Ruei-Hung Kuo², Cheng-Hsien Chiang³

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 90-91, 2019, DOI:10.32604/mcb.2019.07854

Abstract Pulsating flow in a human aortic arch is studied from its kinematic and dynamic characteristics of transient tubular boundary layer. The results can only be obtained by a 3D fluid dynamic (CFD) analysis for the rapidly accelerated and decelerated systolic flow. The flow is based on a prescribed inlet velocity, V_O(t), which can be expressed as the instantaneous Reynolds number, Re(t) = ρDV_O/μ in which D is the tube diameter, ρ the blood density and μ the dynamic viscosity. Computation of pressure field requires a reference pressure at the downstream end section. The pressure is based on the pulse in… More >