莫高窟窟门对窟内热环境影响研究

Influence of the Door of Mogao Grottoes on the Thermal Environment Inside the Cave

莫高窟洞窟均为单侧开口形式,窟门是窟内外空气交换的唯一途径。为研究窟门对窟内热环境稳定的影响,以第206窟、第209窟为例,通过现场测试方法,分析不同窟门洞窟在冬季、秋季窟内热环境的特点;通过数值模拟方法,比较窟门的百叶窗面积发生改变时,第206窟冬季分别在热压作用下、热压风压共同作用下,洞窟沿进深方向的温度影响范围。结果表明:在冬季,第206窟、第209窟窟门漏风量分别为0.01 m^(3)/s、0 m^(3)/s,窟门漏风量越小,窟内温度波动越小;第206窟、第209窟窟门传热系数分别为6.7 W/(m^(2)·K)、2.3 W/(m^(2)·K),在秋季,窟门传热系数越小,洞窟入口处的温度波动越小;第206窟在热压作用下,洞窟的温度影响范围随窟门百叶窗开口面积的增大而增大,最大为2.2 m,在热压风压共同作用下温度影响范围均为6.8 m,达到整个洞窟。

Mogao Grottoes are all in the form of one side openings,and the cave door is the only way to exchange air inside and outside the cave.In order to study the influence of cave door on the stability of thermal environment in cave,the cave 206 and cave 209 are investigated,the characteristics of thermal environment in different caves in winter and autumn were analyzed by means of field measurement.Through the numerical simulation method,when the louver area of the cave door changes,the temperature influence range along the depth direction of cave 206 are compared under the heat pressure and the heat pressure and wind pressure in winter.The results show that,in winter,the air leakage rate at the door of cave 206 and cave 209 are 0.01 m^(3)/s and 0 m^(3)/s,respectively,the smaller the air leakage rate at the door,the smaller the temperature fluctuation in the cave;The heat transfer coefficients of the doors of cave 206 and cave 209 are 6.7 W/(m^(2)·K)and 2.3 W/(m^(2)·K),respectively,In autumn,the smaller the heat transfer coefficient of the cave door is,the smaller the temperature fluctuation at the entrance of the cave is.Under the heat pressure,the influence range of temperature of cave 206 increases with the increase of the opening area of the louver,the maximum is 2.2 m,and under the heat pressure and wind pressure,the influence range of temperature is 6.8 m,reaching the whole cave.