热工实验报告教材.docx

常功率平面热源法同时测定绝热材料的导热系数λ和导温系数 a数据处理：原始数据整理：（原始数据表格见附录）S=0.007854m2 x1=0.015 试验箱编号：TPE-P120τ/mint1/℃t2/℃t3/℃t4/℃P/W017.4117.0619.216.80221.9717.3619.2170.62424.4518.2419.3170.63626.4919.319.317.10.62828.1420.2519.3217.10.621019.8121.1619.3217.10.641231.1622.0719.3517.10.641432.2922.8619.3517.10.631633.3423.7119.4717.20.621834.0324.4119.4717.20.622034.5725.419.4717.20.61关于高斯误差补函数的方程编写高斯误差补函数的一次积分高斯误差补函数的一次积分的反函数数据处理脚本结果表格τ/mina/m2/slamda/W/mK23.8630E-070.066543.7643E-070.061163.7161E-070.056783.6029E-070.0546103.4217E-070.0531123.2250E-070.0509143.1518E-070.0495163.1736E-070.0488183.2808E-070.0504203.4767E-070.0522曲线绘制热源温度t1和距热源x1处温度t2随时间τ的变化关系导热系数lamda随时间的变化导热系数a随时间的变化可以看出λ和a均随时间先降低后升高。因为导热初期，温差小，恒定热流，所以传热快，随着时间的增加，导热变慢。当温度增加到一定程度，温差缩小，导热又逐渐变快。理解分析改变导热系数lamda对温升曲线的影响Lamda变大，温升降低。改变导温系数a对温升曲线的影响a变大，温升变大。空气横掠单圆管时强迫对流换热实验数据处理原始数据整理：（原始数据表格见附录）管号fV0/VV/VU/VUR/mVT1/mVT2/mVT3/mVT4/mVTf/mVA100.4030.45193.6762.763.2313.2473.2243.2300.680A12作废作废作废作废作废作废作废作废作废A150.4030.51193.7462.802.8602.8742.8512.8570.787B100.3970.461142.30131.625.0385.0425.0434.9910.684B120.3970.486143.39135.235.1265.1275.1295.0740.774B150.3970.539144.02122.304.0524.0474.0524.0020.784结果表格管号ftw/℃tf/℃Q/WS/m2h/W/m2Ktm/℃A1080.8317.0058.752.924E-0223.848.91A12作废作废作废作废作废作废A1571.5119.6858.832.924E-0231.445.59B10125.7117.10187.125.942E-0219.571.41B12127.8519.35193.725.942E-0220.473.60B15100.9619.60175.995.942E-0227.960.28查表并用上表中的数据计算可得：tm/℃rho/kg/m3λ/W/mKν/m2/sv/m/su/m/s48.911.09690.02821.784E+019.361.92作废作废作废作废作废作废45.591.10840.02801.751E+0113.962.8671.411.02490.02972.017E+0111.182.7073.601.01860.02992.041E+0113.223.2060.281.05910.02901.900E+0116.383.96利用上表中已经得到的数据即可以得到无量纲数Nu和Re，列表如下：管号fh/W/m2Ku/m/sλ/W/mKν/m2/sD/mNuReA1023.81.920.028217.841.980E-021.672E+012.126E+03A12作废作废作废作废作废作废作废A1531.42.860.028017.511.980E-022.223E+013.232E+03B1019.52.700.029720.173.982E-022.610E+015.340E+03B1220.43.200.029920.413.982E-022.709E+016.244E+03B1527.93.960.029019.003.982E-023.825E+018.306E+03曲线拟合将得到的无量纲数转换成对数并做图：管号fReNulog Relog NuA1