Development of automotive air-conditioning system basic performance simulator: CFD technique development

Kitada, Motohiro; Asano, Hideo; Kanbara, Masahiro; Akaike, Shigeru

doi:10.1016/s0389-4304(99)00077-6

Cited by 17 publications

(14 citation statements)

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“…Since the air flow inside the HVAC module has three-dimensional (3D) unsteady flow characteristics, it is not easy to measure it experimentally. Hence, most previous studies on isothermal ventilation flows inside an automotive HVAC module have been performed through simple flow visualization or numerical simulations (Aroussi et al, 2001;Bennett et al, 2002;Kitada et al, 2001;Shojaee et al, 2004). Several experimental studies accessed the air flow inside the HVAC module using point-wise measurement techniques such as a hot-wire anemometer, a five hole probe, and laser doppler velocimetry (LDV).…”

Section: Regular Papermentioning

confidence: 99%

Investigation on the flow characteristics inside an automotive HVAC system with varying ventilation mode

Kang

Lee

2009

J Vis

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The ventilation flow in a heating, ventilation and air conditioning (HVAC) module of a passenger car was investigated experimentally. Three different ventilation modes with varying temperature mode were tested to study the effect of ventilation mode on the velocity field inside the HVAC module. For each mode, more than 450 instantaneous velocity fields were measured using a particle image velocimetry (PIV) velocity field measurement technique. The instantaneous velocity fields were ensemble averaged to obtain the spatial distribution of mean velocity and spanwise vorticity. The present work highlights the usefulness of the PIV technique for the analysis of the flow inside an HVAC module. The experimental results can be used not only to understand and improve the ventilation flow of an HVAC module but also to validate numerical predictions.

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Section: Regular Papermentioning

confidence: 99%

Investigation on the flow characteristics inside an automotive HVAC system with varying ventilation mode

Kang

Lee

2009

J Vis

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“…The cross-flow type mixing T-junction is also found in the HVAC (Heating, Ventilating and Air-conditioning) unit used for an automobile air-conditioning system. Figure 1 shows a cross-sectional view of the automobile HVAC unit, which contains a fan, an evaporator and a heater-core in a plastic housing (Kitada, et al, 2000, Hirota, et al, 2010. All air taken by the fan is once cooled by the evaporator and humidity is reduced as well, then a part of this cold air is heated by the heater-core.…”

Section: Introductionmentioning

confidence: 99%

Promotion and control of turbulent mixing of hot and cold airflows in T-junction

Matsuda

Hirota

Asano

et al. 2014

JFST

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An experimental study was conducted on the promotion and control of turbulent mixing of hot and cold airflows in a rectangular channel with a T-junction, which simulated an HVAC unit for automobile air-conditioning system. A delta-wing row was installed on the bottom wall of the main channel before the T-junction to promote and control the turbulent thermal mixing. The mean temperature and velocity distributions were measured in several cross sections after the flow merging by thermocouples and PIV, respectively, and the flow in the mixing region was visually observed as well. The development of the thermal mixing layer was promoted effectively by delta wings and the degree of thermal mixing could be controlled by changing the angle of attack of wings. Longitudinal vortices produced by delta wings disappeared just after the merging of two flows, but high turbulence generated by the interaction of those vortices and the branch flow was maintained to further downstream cross sections. The proper orthogonal decomposition analysis was applied to the fluctuating concentration and the fluctuating velocity fields to extract the dominant spatial structures in the T-junction. It was suggested that longitudinal vortices with clockwise and counter-clockwise rotations were shed alternately just behind each delta wing.

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“…In thermal equipments, a T-junction in which two flows with different velocities and temperatures are mixed turbulently is often encountered: one of the typical mixing T-junction can be found in the HVAC (Heating, Ventilating, Air-Conditioning) unit used for an automobile air-conditioning system (1) . Figure 1 shows a schematic diagram of the HVAC unit.…”

Section: Introductionmentioning

confidence: 99%

“…The flow-rate ratio of hot and cold air is determined by the opening of the air-mix door that is located between two heat exchanges (1) . Thus, in the HVAC unit, the hot and cold airflows impinge at nearly right angles with various velocity ratios depending on the air temperature required in the cabin.…”

Section: Introductionmentioning

confidence: 99%

“…This is because the flow field in the Tjunction shows considerably complex features accompanied by the flow separation and reattachment, secondary flow, anisotropy of turbulent stresses, etc., and the present turbulence models cannot predict such complex flows with sufficient reliability. In addition to turbulence models, the modeling of the turbulent heat fluxes in such a complex flow is also a key issue for improving the reliability of numerical simulations of the turbulent thermal mixing in the HVAC unit (1) . Although detailed experimental data are indispensable to the development and evaluation of the turbulence and turbulent heat flux models, they are quite scarce now even in relatively simple flow geometries.…”

Section: Introductionmentioning

confidence: 99%

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Three-Dimensional Structure of Turbulent Flow in Mixing T-junction

Hirota

Asano

Nakayama

et al. 2006

JSME international journal. Ser. B, Fluids and thermal engineer

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Experimental results on the turbulent mixing of hot and cold airflows in a T-junction are reported, which simulates the HVAC unit used in an automobile air conditioning system. Experiments are conducted keeping Reynolds number and temperature of the main flow at 2.5 × 10 4 and 12• C, respectively, and the velocity of the branch flow (60 • C) is changed for three velocity ratios of 0.5, 1 and 2. The flow from the branch is separated at the edge of the T-junction and forms a large separation bubble. Longitudinal vortices are formed around this separation bubble, thus the flow field has a three-dimensional structure. In spite of such a complex flow field, the mean temperature in the thermal mixing layer shows quite uniform distributions in the spanwise direction, and the strong turbulence produced around the separation bubble does not work effectively to the thermal mixing of hot and cold airflows.

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Development of automotive air-conditioning system basic performance simulator: CFD technique development

Cited by 17 publications

References 0 publications

Investigation on the flow characteristics inside an automotive HVAC system with varying ventilation mode

Investigation on the flow characteristics inside an automotive HVAC system with varying ventilation mode

Promotion and control of turbulent mixing of hot and cold airflows in T-junction

Three-Dimensional Structure of Turbulent Flow in Mixing T-junction

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