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冰川冻土 ›› 2015, Vol. 37 ›› Issue (1): 183-191.doi: 10.7522/j.issn.1000-0240.2015.0021

• 寒区科学与技术 • 上一篇    下一篇

基于移动网格技术的热融湖动态演化过程数值模拟

杨振1,2, 温智1, 马巍1, 孙志忠1, 牛富俊1, 俞祁浩1   

  1. 1. 中国科学院 寒区旱区环境与工程研究所 冻土工程国家重点实验室, 甘肃 兰州 730000;
    2. 煤炭工业郑州设计研究院股份有限公司, 河南 郑州 450007
  • 收稿日期:2014-07-11 修回日期:2014-12-22 出版日期:2015-02-25 发布日期:2015-03-23
  • 通讯作者: 温智,E-mail:wenzhi@lzb.ac.cn. E-mail:wenzhi@lzb.ac.cn
  • 作者简介:杨振(1990-),男,安徽阜阳人,2014年在中国科学院寒区旱区环境与工程研究所获硕士学位,现主要从事岩土工程设计与研究.E-mail:yangzhen1954@163.com
  • 基金资助:

    国家自然科学基金项目(41171059; 41471061; 40801024); 国家重点基础研究发展计划(973计划)项目(2012CB026101); 中国科学院"百人计划"项目(Y251561001); 冻土工程国家重点实验室自主课题(SKLFSE-ZY-12)资助

Numerical simulation on the dynamic evolution process of thermokarst lake based on the moving mesh technology

YANG Zhen1,2, WEN Zhi1, MA Wei1, SUN Zhizhong1, NIU Fujun1, YU Qihao1   

  1. 1. State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China;
    2. Zhengzhou Design and Research Institute of Coal Industry Co., Ltd., Zhengzhou 450007, China
  • Received:2014-07-11 Revised:2014-12-22 Online:2015-02-25 Published:2015-03-23

摘要:

基于移动网格技术建立了热融湖动态演化有限元数值模型, 研究了青藏高原多年冻土区典型热融湖动态演化过程, 分析了热融湖半径、深度的变化过程及其对湖底及周围多年冻土温度状况的影响. 结果表明:在移动边界热融湖模型中, 热融湖半径以0.7 m·a-1的速度近线性地增大; 随着下伏高含冰量冻土的融化, 热融湖深度增加先慢后快, 最后逐渐减小趋于稳定. 热融湖深度和半径从5月末至翌年1月末增加显著, 在2-5月间基本保持稳定. 伴随着热融湖的扩展, 地表边界逐渐演变为湖底边界, 热融湖的热影响范围逐渐增大. 在固定边界热融湖模型中, 其热影响会逐渐趋于稳定, 由于初始尺寸大, 其湖底多年冻土退化速率大于移动边界模型, 而远离湖边的多年冻土退化速率要小于移动边界模型. 如果不考虑热融湖边界随时间的变化, 可能会高估热融湖对湖底多年冻土的热影响, 而低估其对附近多年冻土的热影响.

关键词: 移动网格, 热融湖, 数值模拟, 地温状况

Abstract:

Based on the method of moving mesh, a heat transfer finite element numerical model with phase change under cylindrical system was presented. The thermal change and morphologic process of thermokarst lakes were investigated. The results showed that the thermokarst lake expanded at a linear rate of 0.7 m·a-1. The depth of the lake increased with the thawing of ice-rich permafrost. The increasing rate in depth was slow at first, then it became fast, finally it kept constant. The process of expansion and the settlement of the lake was significant during the period of May to Jan. next year, while they were suspended from Feb. to May. The scope of thermal effect increased gradually in the moving boundary model, while it increased firstly and then kept constant in the fixed boundary model. The results showed that the fixed boundary model may overestimate the thermal effect on permafrost under the thermokarst lake and underestimate the thermal effect on permafrost far from the lake.

Key words: moving mesh, thermokarst lake, numerical simulation, thermal regime

中图分类号: 

  • P642.14