Study On The Atria Regulatory Mechanism Of Thermal And Moisture Environment In The Mogao Grottoes

Mogao grottoes are located at southeast of Dullhuang,25kilometers from Dunhuangcity, dug in east cliff of Mingsha mountain, about1600meters long from south to north.wall paintings and statures are existing in492caves, except5caves are located in thenorth area, the others are in the south area. The Mogao grottoes, the first National keyheritage sites unit listed in1961, and written on world heritage list by the UNESCO in1987.In history, the mogao grottoes cave is consists of two parts, the main room and atriaroom, but because of man-made and natural disasters, most of the caves`atria roomhave collapsed, which directly led to the lack of buffer layer between the outsideclimate environment and main cave space. Main indoor`s micro environment moreeasily receive the influence of the external climate environment. Some scholars believethat the disease of mogao grottoes frescoes is caused by the change of microenvironment of cave space.The existence of the caves atria is beneficial to maintain thestability of the microenvironment cave, but the atria regulation mechanism for microcave environment is lack of further study.Firstly,this paper analyzed many grottoes`s temperature and humidity monitoringresults.Through this analysis，we get the the spatial distribution law of temperature andhumidity in caves，and also the the relationship of temperature and humidity betweenatmospheric environment and cave indoor environment. Cave temperature fluctuationsis relatively stable, being affected by the fluctuation of the outdoor air temperature. Thelaw of Grottoes humidity change is relatively complex, the change of humidity between indoor and outdoor has certain correlation, but not identical, and there is a certain lag. Inaddition, the farther distance tunnel, the temperature affected by the external fluctuationis smaller, which said the remaining atria i have certain effect to resist the externalenvironment of volatility.For buffer space, this paper established the physical model of buffer space. On thisbasis, the mathematical model of buffer space was derived,and Designbuilder was usedto solve mathematical model.In addition,this paper simulates the thermal environmentof the131caves with atria and without atria.Through the analysis,we can get theconclusion that the existence of atria plays an important role at the stable thermalenvironment.Finally, on the basis of studying the atria`s regulation mechanism, this article makesa preliminary study to recover the mogao grottoes`atria. On the basis of the originalappearance,we adopt new technology and new method to re-design the door, and bysetting the air layer, the method of reducing the grottoes air relative humidity.