Study on Practical Application of the Numerical Prediction Method of Indoor Air Distribution
Grant-in-Aid for General Scientific Research (B)
|Allocation Type||Single-year Grants |
|Research Institution||University of Tokyo |
KAMATA Motoyasu Univ. of Tokyo, Faculty of Engineering Associate Proffesor, 工学部, 助教授 (70011228)
KURABUCHI Takashi Univ. of Tokyo, Faculty of Engineering Assistant, 工学部, 助手 (70178094)
CHIDA Yoshitaka Univ. of Tokyo, Faculty of Engineering Assistant, 工学部, 助手 (00107559)
|Project Period (FY)
1989 – 1991
Completed (Fiscal Year 1991)
|Budget Amount *help
¥5,400,000 (Direct Cost: ¥5,400,000)
Fiscal Year 1991: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1990: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1989: ¥3,400,000 (Direct Cost: ¥3,400,000)
|Keywords||Numerical Analysis / Turbulence / k-epsilon model / MAC method / Indoor Airflow / Wall Boundary Condition / Buoyancy / Composite Grid / Kーεモデル / 数値流体力学 / 乱流モデル / k-ε型二方程式モデル / 模型実験 / 傾斜吹き出し / 局所差分分割 / CG法|
This study aims at extending range of application of the current numerical prediction method of indoor airflows to more realistic engineering problems. The research activity has been focused on the improvement of the finite-difference solution method, and the validation of buoyancy extended turbulence model and wall boundary condition. The main results of the study are summarizedas follows.
1. Improvement of the finite-difference method.
(1) Numerical simulation based on the conventional MAC method is carried out for indoor airflows ventilated by diffusers of different supply angles. According to the post error analysis, it is stressed that fine mesh is required near the diffusers to generate accurate prediction especially in case oblique jet flow and its diffusion characteristics are to be predicted.
(2) In order to make efficient and accurate prediction based on the conventional finite-difference approach, a local refinement technique of the MAC mesh systems is developed. The reliabilit
y of the method is carefully chocked for fundamental indoor airflow problems.
(3) The method is applied to airflow induced with complicated supply diffusers, and combined flow for cross ventilation of buildings. The accuracy of the simulated results are partially supported by the experiment data. and the feasibility of the method to complicated problems is demonstrated.
2. Numerical simulation of non-isothernal indoor airflow.
(1) Different models of the epsilon transport equations for buoyancy influenced turbulent airflows are assesed through experimental validations. It is concluded that the Viollet model produces most realistic solution, and is considered applicable for wide range of practical engineering flows.
(2) The convective heat transfer coefficient over a vertical heated plate is calculated using different type wall boundary conditions. The comparisons to the available data show that a wall function of the turbulence kinetic energy type accounting for the viscous sublayer effect exerts the smallest grid dipendency, and produces the most close solution to the experiments.
(3) In order to find out accuracy of the above method for practical air-conditioned room case, numerical simulation is carried out and the results are compared to full scale model experiments. It is clarified that the current numerical scheme can reproduce sufficiently accurate results including spatial variations of convective heat transfer coefficient as for at fully turbulent indoor airflow of high Reynolds number is concerned. Less
Report (4 results)
Research Products (50 results)