...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Experimental Thermal and Fluid Science: International Journal of Experimental Heat Transfer, Thermodynamics, and Fluid Mechanics >Fire-induced flow of smoke and hot gases in open vertical enclosures
【24h】

Fire-induced flow of smoke and hot gases in open vertical enclosures

机译：由火引起的烟雾和高温气体在开放式垂直机柜中的流动

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

An experimental study on the flow and heat transfer in open vertical enclosures, representing elevator shafts, warehouses, and atriums, due to a building fire is carried out, using a scale model. Smoke and hot gases are injected into the enclosure at a lower opening and the resulting downstream flow and temperature fields are studied. The inlet temperature and flow rate of the hot gases are varied over wide ranges to simulate the flow due to fire in multi-leveled buildings with vertical open shafts or atriums under natural ventilation. The conditions at the outlet, which is located on the same wall as the inlet, are also monitored to determine the effects of entrainment into the flow and heat transfer to the walls. Typical values of the operating conditions have been investigated, ranging from high buoyancy levels, for which the flow stays close to the vertical wall of the enclosure, to much lower levels, at which the flow enters the enclosure with a significant flow velocity and spreads outward very quickly. With increasing temperature at the inlet, the buoyancy effect is larger, resulting in higher velocities and shorter time to reach the top. The measured temperature at the outlet depends on heat transfer to the walls as well as on the flow velocity. Detailed measurements of the velocity and temperature fields have also been taken. It is sound that a wall plume is generated which conveys the hot fluid rapidly along the vertical wall containing the inlet and the outlet. A recirculating flow arises away from this wall and this flow affects the heat transfer and flow in the wall plume. This feature, in turn, affects the entrainment into the flow, decay of the temperature level and the evolution of mean flow. Therefore, horizontally uniform conditions cannot be assumed here, as employed in several studies of tall enclosures. The wall plume has to be modeled in this case, considering the entrainment into the boundary layer flow and the effect of the recirculating flow.
机译：使用比例模型，对由于建筑物起火而导致的电梯竖井，仓库和中庭在开放式垂直围护结构中的流动和传热进行了实验研究。将烟气和热气从较低的开口处注入外壳，并研究由此产生的下游流场和温度场。高温气体的入口温度和流量在很大范围内变化，以模拟自然通风条件下带有垂直敞开井道或中庭的多层建筑中火灾引起的流量。还监视与进口位于同一壁上的出口处的状况，以确定夹带到流中的影响以及热量向壁的传递。已经研究了操作条件的典型值，范围从高浮力水平（对于该浮力水平，该流保持接近外壳的垂直壁）到低得多的水平，在该水平下，该流以显着的流速进入外壳并向外扩散很快随着入口温度的升高，浮力效果会更大，从而导致更高的速度和更短的到达顶部的时间。出口处测得的温度取决于传至壁的热量以及流速。还已对速度和温度场进行了详细的测量。听起来会产生壁羽，该壁羽沿包含入口和出口的垂直壁快速输送热流体。离开该壁而产生再循环流，并且该流影响壁羽流中的热传递和流。反过来，此功能会影响气流的夹带，温度水平的衰减和平均气流的演变。因此，如对高围墙的多次研究所采用的，此处不能假定水平均匀的条件。在这种情况下，必须对壁羽建模，要考虑到夹带进入边界层流和再循环流的影响。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号