| 摘要: |
| 【目的】对季节性冻土区衬砌渠道在太阳辐射作用下的温度场进行数值模拟，分析太阳辐射对渠道温度分布的影响。【方法】利用Hottel太阳辐射模型，结合热传导理论和有限元分析方法，考虑渠道自身的遮蔽作用，对太阳辐射作用下的梯形衬砌渠道的温度场进行计算。【结果】提出了梯形渠道太阳辐射的计算方法；衬砌渠道表面太阳辐射的日变化表现为早晚最小、中午最大；渠道阴、阳坡接受到的太阳辐射差异明显，阴坡太阳总辐射约为阳坡的20%；渠道表面温度的日变化趋势与大气温度相同，近似为正弦分布，其温度变幅小于大气温度变幅，变化滞后于太阳辐射约2.5 h，阴、阳坡温度最大相差4 ℃左右，阳坡温度值与日间温度增加速率均大于阴坡。【结论】渠道温度变化与太阳辐射有密切关系，阴、阳坡接受到的太阳辐射量不同是渠道温度存在较大差异的原因，太阳辐射是渠道冻融循环的动力，在渠道冻胀研究中必须考虑太阳辐射的影响。 |
| 关键词: 季节性冻土 衬砌渠道 温度场 太阳辐射 |
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| 基金项目:国家自然科学基金项目(51279168)；冻土工程国家重点实验室基金项目(SKLFSE201105)；国家科技支撑计划项目(2012BAD10B02)；陕西省水利科技计划项目(SXSL2011-03)；陕西农业科技创新项目(2011NXC01-20) |
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| Temperature field of lining canal in freezing period under solar radiation |
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| Abstract: |
| 【Objective】This study simulated the temperature field of lining canal under solar radiation in seasonal frozen area.【Method】Based on Hottel model,heat transfer theory and finite element method,the temperature field of lining canal was calculated with the defilade of canal.【Result】The calculation method of solar radiation on trapezoidal canal was proposed.The maximum value of solar radiation was at noon.The diurnal variation of solar radiation and the temperatures on different slopes were carried out.The amounts of solar radiation on different slopes were quite different,solar radiation on shady slope was 20% of that on sunny slope.Surface temperature distributed as a shape of sinusoid.The variation of surface temperature was about 2.5 hours later than solar radiation variation.Variation range of surface temperature was smaller than that of ambient temperature.The difference between maximum temperatures on shady and sunny slopes was about 4 ℃.The value and increasing speed of temperature on sunny slope were higher than those on shady slope.【Conclusion】Temperature of canal and solar radiation are closely related.The variations of solar radiation on different slopes and ambient temperature are the causes of temperature differences.Solar radiation is the motivation of freeze-thaw cycles,and need to be considered in the study of frost heaving in lining canal. |
| Key words: seasonal frozen soil lining canal thermal field solar radiation |
