柔性基底表面液滴蒸发传热特性实验研究

doi:10.11949/0438-1157.20250846

摘要/Abstract

摘要：

液滴在柔性基底上的蒸发现象广泛存在于柔性电子设备、生物医学等领域，其传热机理研究对设备散热设计具有重要指导意义。本文选取正戊烷为工质，在固化比为10：1和50：1的PDMS基底上开展蒸发实验，分析了表面柔性特性对液滴蒸发过程中界面温度及热通量分布的影响。实验采用非接触式温敏漆（Temperature Sensitive Paint， TSP）获取温度场分布，建立一维非稳态导热模型计算固-液界面热通量，并结合红外相机观测结果进行对照验证。结果表明：相较于10：1的柔性基底，液滴在固化比50：1的PDMS基底表面上蒸发速率更快，平均温度降低 0.7%-1.6%，平均热通量增大16%-25%。

关键词: 柔性基底, 温敏漆, 液滴蒸发, 温度分布

Abstract:

The evaporation of droplets on flexible substrates is a common phenomenon in fields such as flexible electronic devices and biomedicine, and research on its heat transfer mechanism is of great guiding significance for the thermal management design of devices. In this paper, n-pentane is selected as the working fluid, and evaporation experiments are carried out on PDMS substrates with curing ratios of 10:1 and 50:1 to analyze the influence of surface flexibility on the distribution of interfacial temperature and heat flux during droplet evaporation. A non-contact temperature measurement technology (Temperature Sensitive Paint, TSP) is used to obtain the temperature field distribution, and a one-dimensional unsteady heat conduction model is established to calculate the heat flux at the solid-liquid interface, which is verified by comparison with the observation results of an infrared camera. The results show that compared with the flexible substrate with a curing ratio of 10:1, the droplets evaporate faster on the PDMS substrate surface with a curing ratio of 50:1, with the average temperature decreasing by 0.7%-1.6% and the average heat flux increasing by 16%-25%.

Key words: flexible substrate, temperature-sensitive paint, droplet evaporation, temperature distribution

中图分类号:

O 359

刘璐, 李玉平, 熊巧铃, 王腾. 柔性基底表面液滴蒸发传热特性实验研究[J]. 化工学报, DOI: 10.11949/0438-1157.20250846.

Lu LIU, Yuping LI, Qiaoling XIONG, Teng WANG. Experimental study on heat transfer characteristics of droplet evaporation on flexible substrate surfaces[J]. CIESC Journal, DOI: 10.11949/0438-1157.20250846.

图/表 16

图1 固化比为10:1的PDMS（a）和固化比为50:1的PDMS（b）在25℃下的AFM图像

Fig. 1 AFM images of the PDMS surfaces at 25 °C: （a） 10:1, （b） 50:1.

图2 不同固化比下PDMS储能模量G'和损耗模量G''随频率变化情况

Fig. 2 . Variation of the storage modulus G' and loss modulus G'' of PDMS under different conditions with frequency.

图3 实验系统示意图

Fig. 3 Schematic diagram of the experimental system

图4 TSP的激发光谱及发射光谱

Fig. 4 Excitation and emission spectra of TSP

图5 温度标定曲线

Fig. 5 Temperature calibration curve

图6 液滴蒸发固-液界面热通量计算模型示意图

Fig. 6 Schematic diagram of the calculation model for heat flux at the solid-liquid interface during droplet evaporation

表1 1个大气压、25℃条件下正戊烷物性参数

Table 1 Physical properties of n-pentane at 1 atmosphere and 25°C

工质

c_P

$J ⋅ k g - 1 ⋅ K - 1$

$W ⋅ m - 1 ⋅ K - 1$

L_V

$k J ⋅ k g - 1$

$m P a ⋅ s$

$m N ⋅ m - 1$

Tsat

$℃$

表1 1个大气压、25℃条件下正戊烷物性参数

Table 1 Physical properties of n-pentane at 1 atmosphere and 25°C

工质

c_P

$J ⋅ k g - 1 ⋅ K - 1$

$W ⋅ m - 1 ⋅ K - 1$

L_V

$k J ⋅ k g - 1$

$m P a ⋅ s$

$m N ⋅ m - 1$

Tsat

$℃$

正戊烷

2296

0.117

367

0.22

18.0

图7 正戊烷液滴在固化比10:1的PDMS蒸发过程的固-液界面温度图，界面热通量图，红外图像

Fig. 7 Interface temperature map, interfacial heat flux map, and infrared image of the solid-liquid interface during the evaporation process of n-pentane droplets on PDMS with a curing ratio of 10:1

图8 液滴中轴线及液滴中心示意图

Fig. 8 Schematic diagram of the droplet's central axis and droplet center

图9 两种测温方式测量液滴中心温度随时间变化

Fig. 9 Measurement of the droplet's central temperature variation over time using two temperature measurement methods

图10 正戊烷液滴在固化比为10:1的PDMS蒸发过程（a）温度分布和（b）热通量分布随时间变化

Fig. 10 （a） Temperature distribution and （b） heat flux distribution at the contact surface over time during the evaporation process of an n - pentane droplet on PDMS with a mass ratio of 10:1

图11 正戊烷液滴在固化比50:1的PDMS蒸发过程的界面温度图，界面热通量图，红外图像

Fig. 11 Interface temperature map, interface heat flux map, and infrared image during the evaporation process of an n - pentane droplet on PDMS with a mass ratio of 50:1

图12 正戊烷液滴在固化比为50:1的PDMS蒸发过程温度分布（a）热通量分布（b）随时间变化

Fig. 12 （a） Temperature distribution and （b） heat flux distribution at the contact surface over time during the evaporation process of an n - pentane droplet on PDMS with a mass ratio of 50:1

图13 正戊烷液滴在不同固化比PDMS表面蒸发过程中无量纲时间下液滴接触直径的变化图像

Figure 13 Images of the variation in contact diameter of n-pentane droplets at the dimensionless time during evaporation on PDMS surfaces with different curing ratios

图14 正戊烷液滴在不同固化比PDMS上蒸发过程的平均温度（a）和平均热通量（b）随时间变化

Fig. 14 （a） Mean temperature and （b） mean heat flux over time during the evaporation process of an n - pentane droplet on PDMS with different mass ratios

表2 液滴于PDMS蒸发过程热流量校核结果

Table 2 Verification results of the heat flux during the droplet evaporation process on PDMS

PDMS固化比	Q_TSP（J）	Q_th（J）	相对误差 $Q T S P - Q t h Q t h × 100 %$
10:1	3.372	2.936	14.85
50:1	3.258	2.936	10.97

表2 液滴于PDMS蒸发过程热流量校核结果

Table 2 Verification results of the heat flux during the droplet evaporation process on PDMS

PDMS固化比	Q_TSP（J）	Q_th（J）	相对误差 $Q T S P - Q t h Q t h × 100 %$
10:1	3.372	2.936	14.85
50:1	3.258	2.936	10.97

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