期刊文献+
共找到6篇文章
< 1 >
每页显示 20 50 100
基于不同涡黏模型的三心拱巷道风流数值模拟研究
1
作者 程熙宇 周春山 陈鹏燕 《矿业安全与环保》 CAS 北大核心 2024年第3期97-106,共10页
为了研究不同湍流模型在预测U形钢支护三心拱巷道截面风速分布的差异性,选取相同边界条件下风洞实测风速与基于标准k-epsilon模型、标准k-omega模型、Spalart-Allmaras模型等3种湍流模型的仿真风速进行比较。结果表明,上述3种湍流模型... 为了研究不同湍流模型在预测U形钢支护三心拱巷道截面风速分布的差异性,选取相同边界条件下风洞实测风速与基于标准k-epsilon模型、标准k-omega模型、Spalart-Allmaras模型等3种湍流模型的仿真风速进行比较。结果表明,上述3种湍流模型均能大致描述巷道风流特征,巷道截面处风速实测值与仿真值的绝对误差与入口风速呈正相关关系,与壁面距离呈负相关关系;以绝对误差平均值和均方根误差为评判准则,标准k-epsilon模型在模拟巷道风速时与现场实测风速数据的拟合度较高,Spalart-Allmaras模型次之,标准k-omega模型拟合度较低。 展开更多
关键词 三心拱巷道 U形钢支护 计算流体力学 数值模拟 涡黏模型 风流特征
下载PDF
基于风流运动的粉尘运移研究进展及趋势
2
作者 姜伯洋 齐艺裴 +3 位作者 张嘉勇 郭立稳 李嘉 肖洋 《煤炭与化工》 CAS 2024年第7期123-128,共6页
矿井机械化、智能化水平提升所导致的粉尘问题愈发严重,探究风流-粉尘运移规律,掌握工作面风流、粉尘的运动特征,对改进工作面控尘措施,改善井下作业环境,加速实现绿色矿山目标具有重要意义。通过查阅国内外文献资料,调研相关研究进展... 矿井机械化、智能化水平提升所导致的粉尘问题愈发严重,探究风流-粉尘运移规律,掌握工作面风流、粉尘的运动特征,对改进工作面控尘措施,改善井下作业环境,加速实现绿色矿山目标具有重要意义。通过查阅国内外文献资料,调研相关研究进展与实践经验,从粉尘受力运动原理、相似实验设计、数值模拟研究、组合方法效果评估等方面,研究当前风流场及其对粉尘分布的影响,认为当前存在风流场与粉尘之间相互作用复杂,粉尘受力运动机理与运动路径研究不透彻,不同因素组合作用与粉尘运移规律关系不明朗等问题。从提高规律向实用性和普遍性转变的角度,提出风流-粉尘运移规律的研究重点应向明晰粉尘运移受力机理和作用力协同机制、建立多参数表征运移规律、提升监测仪器精密度、减弱次要因素对相似实验结果影响程度、增强对风流场和粉尘运移力学特征的认知、明朗影响因素间的耦合关系、构建适用于气-固两相流的数学模型及完善颗粒运动扩散方程8个方面转变。 展开更多
关键词 风流运动特征 粉尘运移规律 控尘措施 因素耦合关系
下载PDF
岩巷产尘规律及控风除尘技术研究 被引量:6
3
作者 邹常富 《煤炭技术》 CAS 北大核心 2021年第4期77-79,共3页
深入分析了机掘岩巷工作面压入式通风的风流运动特征,得出了风流速度及运动规律,并现场测定了掘进机截顶岩、截中部岩矿及扫底作业的粉尘浓度,掌握了迎头粉尘质量浓度分布规律,基于长压短抽通风除尘措施中的弊端,研究了控风控尘措施,形... 深入分析了机掘岩巷工作面压入式通风的风流运动特征,得出了风流速度及运动规律,并现场测定了掘进机截顶岩、截中部岩矿及扫底作业的粉尘浓度,掌握了迎头粉尘质量浓度分布规律,基于长压短抽通风除尘措施中的弊端,研究了控风控尘措施,形成了风流调控与粉尘治理相结合的技术。在现场应用中,结合控风控尘与长压短抽的除尘器抽尘净化措施,司机位置处的降尘效率达99%,且时间加权平均浓度降至2.5 mg/m^(3),保障了掘进机司机免受粉尘危害。 展开更多
关键词 风流特征 产尘规律 粉尘质量浓度 长压短抽 控风除尘
下载PDF
Turbulence regime near the forest floor of a mixed broad leaved/Korean pine forest in Changbai Mountains 被引量:5
4
作者 张军辉 丁之慧 +2 位作者 韩士杰 邹春静 周玉梅 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第2期119-122,164,共4页
The measurement and observation for this study were carried out by using a three-dimensional (u, v, w) Sonic anemometer (IAP-SA 485), at Forest Ecosystem Opened Research Station of Changbai Mountains (12828扙 and 4224... The measurement and observation for this study were carried out by using a three-dimensional (u, v, w) Sonic anemometer (IAP-SA 485), at Forest Ecosystem Opened Research Station of Changbai Mountains (12828扙 and 4224?N, Jilin Province, P. R. China) in August 2001. The basic characteristics of turbulence, such as turbulence intensity, atmospheric stability, time scales, and convection state, near the forest floor were analyzed. It is concluded that the airflow near forest floor is characterized by high intermittence and asymmetry, and the active and upward movement takes the leading position. Near forest floor, the vertical turbulence is retained and its time scale and length scale are much less than that of u, v components. The eddy near forest floor shows a flat structure and look like a ’Disk’. Buoyancy plays a leading role in the generation and maintenance of local turbulence 展开更多
关键词 Forest floor Velocity statistics Atmospheric stability Convection states
下载PDF
Characteristics of Large Low-frequency Debris Flow Hazards and Mitigation Strategies 被引量:3
5
作者 WANGShige 《Journal of Mountain Science》 SCIE CSCD 2005年第1期50-58,共9页
A low-frequency debris flow took place in the north coastal range of Venezuela on Dec. 16, 1999, and scientists all over the world paid attention to this catastrophe. Four characteristics of low-frequency debris hazar... A low-frequency debris flow took place in the north coastal range of Venezuela on Dec. 16, 1999, and scientists all over the world paid attention to this catastrophe. Four characteristics of low-frequency debris hazard are discussed: long return period and extreme catastrophe, special rare triggering factors, difficulty in distinguishing and a series of small hazards subsequent to the catastrophe. Different measures, such as preventing, forecast - warning, engineering, can be used for mitigating and controlling the catastrophe. In engineering practice, it is a key that large silt-trap dams are used to control rare large debris flow. A kind of low dam with cheap cost can be used to replace high dam in developing countries. A planning for controlling debris flow hazard in Cerro Grande stream of Venezuela is presented at the end of this paper. 展开更多
关键词 Low-frequency debris flow mitigation strategies
下载PDF
Climate as the Early Warning of Outbreaks of Leptospirosis in the District of Sampang Madura Island Indonesia
6
作者 Ririh Yudhastuti 《Journal of Environmental Science and Engineering(A)》 2015年第10期541-544,共4页
In Indonesia, most transmission of leptospirosis occurs through the rat under conditions of high rainfall or flooding. Sampang is endemic leptospirosis, during March-May 2013, there were 55 patients with 8 of them die... In Indonesia, most transmission of leptospirosis occurs through the rat under conditions of high rainfall or flooding. Sampang is endemic leptospirosis, during March-May 2013, there were 55 patients with 8 of them died. The purpose of this study was to analyze risk factors for outbreaks leptospirosis by climatic factors. Study is cross-sectional design of variable causes or risks that occur due to the object of research are measured simultaneously. The results showed that the distribution of events is based on epidemiological characteristics of leptospirosis in districts Sampang both rainy and dry season. Analysis of climatic factors show support to the continuation of leptospirosis whose temperatures ranged from 29.35 ~C-30.62 ~C, humidity range between 63.4%-80.5%. Rainfall ranges from 183-190 ram. Incidence of leptospirosis in Sampang shows the distribution of leptospirosis cases from 18 subdistricts, 14 subdistriets are at risk of the occurrence of leptospirosis. Results obtained rat trapping species caught in the neighborhood residential home patients were mice (Rattus tanezumi and Rattus novergicus) and the identification of the leptospira in rat urine sewers rat positive standing of the potential risk of leptospirosis in the community. The conclusions are climatic conditions, rainfall remarkable effecting on the incidence of leptospirosis. 展开更多
关键词 TEMPERATURE relative humidity RAINFALL outbreaks of leptospirosis Sampang district Madura island Indonesia.
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部