全覆い上屋開口部の流れが準定常流と見なせるための圧力条件に関する研究(流体工学,流体機械)

概要

論文の詳細を見る
Shinkansen railwaystations in a snowy district usually have adopted a structure (we call it "a whole covering shed") enclosing the entire track floor with a roof and side walls to keep a good environment of the station. The shed is about 400m in length, and therefore for a train passing through the station this shed is regarded as a short tunnel with large cross section. Openings are provided on the periphery of the shed to decrease the pressure variation generated by the train. The relation between the pressure inside the shed and the velocity of a flow dishcarged from an opening becomes important in the investigation of the problems concerning this pressure variation. The flow velocity is usually calculated from Bernoulli's equation for steady flow, however, the validity of the quasi-steady assumption has not been discussed in detail. In this paper, (1) the relation between the pressure variation in a station shed and the flow velocity discharged from an opening of the shed wall is formulated by using Bernoulli's equation for unsteady flow, and the validity of this formulation is examined by comparing theoretical results with experimental ones; (2) the condition under which Bernoulli's equation for steady flow can be applied in the case of the pressure variation in the station shed is examined.
2010-06-25