静冰生消室内模拟试验研究及关键参数确定

基于嫩江岸冰原位观测数据,开展静冰生消过程室内模拟试验研究并确定关键参数。结果表明,依据模型试验相似关系,确定室内模型试验需考虑关键参数为几何比尺C_l、温度比尺C_T、时间比尺C_t与试验室修正系数C_α;通过建立冰冻度日相似准则,应用相似原理推导得出:(C_l/C_α)~2=C_TC_t;基于原型试验中太阳辐射变化过程对室内模拟试验作合理光照补偿,在确定C_l=19,C_T=1.51条件下,得到试验室修正系数C_α值为0.55,冰厚增长系数α为1.76,时间比尺C_t=137.5;基于模型试验中相同参数,在冰厚生长后期对冰面作光照补偿,对比无光照组冰生消过程,光照补偿可较好模拟野外静冰生消过程,无光照冰厚增长系数α为1.96～1.98,有光照冰厚增长系数α为1.74～1.75,近似于模型比尺后原型α值(1.76);根据原型气温与太阳辐射变化过程,依据相同累积负温原则设计控温曲线,补偿合理光照,获得冰厚增长系数与冰厚生消过程均与原型相近结果。

Laboratory simulation test and key parameters determination of static ice growth and decay processes

Based on the in situ observation data of riparian shore ice, an indoor simulation test of static ice formation and elimination process was carried out and the key parameters were determined,the results showed that according to the similarity of the model test, the key parameters to be determined in the indoor model test were as follows geometric scale C_l, temperature scale C_T, time scale Ctand laboratory correction factor Cα, by establishing the freezing diurnal similarity criterion and applying the similarity principle, it was deduced that(C_l/C_α)~2=C_TC_t. Based on the process of solar radiation variation in prototype test, the indoor simulation test was compensated by reasonableillumination, under the condition of determining C_l=1:9 and C_T=1.5:1, the correction coefficient Cαof the test room was 0.55, the ice thickness growth coefficient was 1.76, and the time ratio was C_t=1:37.5; based on the same parameters in the model test, the ice surface was compensated for illumination at the later stage of ice thickness growth. Compared with no light, the illumination compensation could better simulate the process of field ice production, no light ice thickness growth coefficient α was 1.96-1.98,light ice thickness growth coefficient α was 1.74-1.75, approximate to the prototype value α(1.76) behind the scale of the model; according to the process of prototyping temperature and solar radiation,temperature control curves were designed based on the same cumulative negative temperature principle to compensate for reasonable lighting. The result that both the ice thickness growth coefficient and the ice thickness growth and elimination process were similar to the prototype was obtained.