The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform

Predrag Stojan Hrnjak - One of the best experts on this subject based on the ideXlab platform.

  • a new method to simultaneously measure Local Heat Transfer and visualize flow boiling in plate Heat exchanger
    International Journal of Heat and Mass Transfer, 2017
    Co-Authors: Predrag Stojan Hrnjak
    Abstract:

    Abstract This paper presents the development of a novel method to combine measurement of Local Heat Transfer coefficient and flow visualization in frame-and-plate Heat exchanger (FPHE) simultaneously. A Heat flux plate is built using two original chevron plates and clay as thermal infills. Thermocouples are deployed on the inner surfaces of both plates. With the known thickness and thermal conductivity of the clay, the instrumented plate functions as a Heat flux sensor. After initial calibration, this plate is installed to measure fluid Heat Transfer from one side, while leaving visual access from the other. Preliminary results of water-water single-phase Heat Transfer and R245fa-water flow boiling are presented. Combined with visualization, the method provides a viable solution to relate Local Heat Transfer with flow regime within a plate channel, while preserving the real geometry and operating condition.

Takayuki Tsutsui - One of the best experts on this subject based on the ideXlab platform.

  • Local Heat Transfer around a wall mounted cube in the turbulent boundary layer
    International Journal of Heat and Mass Transfer, 2001
    Co-Authors: Hajime Nakamura, Tamotsu Igarashi, Takayuki Tsutsui
    Abstract:

    Experimental studies were performed to investigate the fluid flow and Local Heat Transfer around a cube mounted on a wall of a plane. The Reynolds number based on the cube height ranged from 4.2×103 to 3.3×104. The turbulent boundary layer thickness δ was 1.5–1.83 times higher than the cube height d. Surface temperatures on the cube and the base wall were measured directly with numerous thermocouples under the condition of constant Heat flux. In the present paper, Local Heat Transfer characteristics on the cube and the base wall were clarified correlating to the flow characteristics. In the range of the present Reynolds number, the overall Nusselt number of the cube can be expressed by .

Hajime Nakamura - One of the best experts on this subject based on the ideXlab platform.

  • Local Heat Transfer around a wall mounted cube in the turbulent boundary layer
    International Journal of Heat and Mass Transfer, 2001
    Co-Authors: Hajime Nakamura, Tamotsu Igarashi, Takayuki Tsutsui
    Abstract:

    Experimental studies were performed to investigate the fluid flow and Local Heat Transfer around a cube mounted on a wall of a plane. The Reynolds number based on the cube height ranged from 4.2×103 to 3.3×104. The turbulent boundary layer thickness δ was 1.5–1.83 times higher than the cube height d. Surface temperatures on the cube and the base wall were measured directly with numerous thermocouples under the condition of constant Heat flux. In the present paper, Local Heat Transfer characteristics on the cube and the base wall were clarified correlating to the flow characteristics. In the range of the present Reynolds number, the overall Nusselt number of the cube can be expressed by .

Tamotsu Igarashi - One of the best experts on this subject based on the ideXlab platform.

  • Local Heat Transfer around a wall mounted cube in the turbulent boundary layer
    International Journal of Heat and Mass Transfer, 2001
    Co-Authors: Hajime Nakamura, Tamotsu Igarashi, Takayuki Tsutsui
    Abstract:

    Experimental studies were performed to investigate the fluid flow and Local Heat Transfer around a cube mounted on a wall of a plane. The Reynolds number based on the cube height ranged from 4.2×103 to 3.3×104. The turbulent boundary layer thickness δ was 1.5–1.83 times higher than the cube height d. Surface temperatures on the cube and the base wall were measured directly with numerous thermocouples under the condition of constant Heat flux. In the present paper, Local Heat Transfer characteristics on the cube and the base wall were clarified correlating to the flow characteristics. In the range of the present Reynolds number, the overall Nusselt number of the cube can be expressed by .

Gianpaolo Ruocco - One of the best experts on this subject based on the ideXlab platform.

  • simultaneous visualization of flow field and evaluation of Local Heat Transfer by transitional impinging jets
    International Journal of Heat and Mass Transfer, 2003
    Co-Authors: M Angioletti, R M Di Tommaso, E Nino, Gianpaolo Ruocco
    Abstract:

    Abstract A combined approach has been employed to characterize the flow field and Local Heat Transfer in jet impingement configurations, featuring a mass Transfer experiment and a digital visualization technique. A jet velocity range is spanned to ensure flow regime transition. The well-known Heat/mass Transfer analogy has been used to infer on the Local Heat exchange on a infinite plate. In this experiment, a naphthalene film is ablated from a disk, due to jet exposure. Automated contact measurements of the variation of film depth in the stagnation region and beyond have been performed. From the Local naphthalene loss rate the Local Heat Transfer is then inferred. Coherent structures are created both at the interface between free jet and quiescent medium and upon impingement at plate, and need to be visualized in the vicinity of stagnation. To this end a particle image velocimetry system is exploited to extract the two components velocity instantaneous information. Ablation measurements confirm the non-monotonic progress of Local Heat Transfer for small nozzle-to-plate spacings. The visualizations evidence that Local Heat Transfer is strongly influenced by impingement structures: the maximum Heat Transfer coefficient offset which can be detected is due, even for laminar or transitional jet, to large-scale toroidal vortices impacting on the plate.