Agustina Dinni, Putra Nandy
Applied Heat Transfer Research Group, Department of Mechanical Engineering, Universitas Indonesia, Kampus UI Depok,16424, Indonesia.
Heliyon. 2023 Feb 24;9(3):e13936. doi: 10.1016/j.heliyon.2023.e13936. eCollection 2023 Mar.
The use of sintered-wick heat pipes in heat exchanger performance-related studies gained popularity owing to the simplicity and affordability of heat pipes. Evaluation of the system performance may be based on various arrangements and numbers of heat pipes applicable to the literature. Wick porosity and permeability are critical parameters for the investigation of wick capillary pumping, which will ultimately determine heat pipe performance. Despite the significance of these parameters to thermal performance, they are difficult to obtain, as the methods for obtaining these parameters before installing the heat pipes are time-consuming and destructive. This study aims to investigate the feasibility of Micro Tomography (Micro CT) to observe the porosity of copper sintered-wick heat pipes. Visual data from three heat pipe samples, namely HP1, HP2, and HP3 are quantified and analyzed. Analysis of the average porosity of HP1 and HP2 samples showed a similar value of 47.6 and 48.1%, respectively; however, the value of porosity along the length of the scanned area shows a bigger range of 42-54%. The accuracy of Micro CT was tested by testing three porosity samples with designed porosity of 26%, 22.3%, and 16.6% which were 3D printed using atomic diffusion additive manufacturing technology. Each sample was designed with pore shapes hexagonal, circular, and elliptical, respectively. Micro CT visualization and analysis showed the porosity reduction of the 3D printed porosity samples compared to the CAD design. Due to the smallest reduction of porosity after the sintered process, the 3D printed sample with a hexagonal pore shape, and the designed porosity of 26%, this sample was recommended for sintered wick fabrication using this technology and to test the accuracy of Micro CT.
由于热管具有结构简单和成本低廉的特点，烧结芯热管在与热交换器性能相关的研究中得到了广泛应用。系统性能的评估可以基于文献中适用的各种热管布置和数量。芯体的孔隙率和渗透率是研究芯体毛细泵送的关键参数，最终将决定热管的性能。尽管这些参数对热性能很重要，但由于在安装热管之前获取这些参数的方法既耗时又具有破坏性，因此很难获得。本研究旨在探讨显微断层扫描（Micro CT）观察铜烧结芯热管孔隙率的可行性。对三个热管样品（即HP1、HP2和HP3）的视觉数据进行了量化和分析。对HP1和HP2样品平均孔隙率的分析表明，其值分别为47.6%和48.1%，较为相似；然而，沿扫描区域长度方向的孔隙率值显示出更大的范围，为42 - 54%。通过使用原子扩散增材制造技术3D打印设计孔隙率分别为26%、22.3%和16.6%的三个孔隙率样品来测试Micro CT的准确性。每个样品分别设计有六边形、圆形和椭圆形的孔形状。Micro CT可视化和分析表明，与CAD设计相比，3D打印的孔隙率样品的孔隙率有所降低。由于烧结过程后孔隙率降低最小，具有六边形孔形状且设计孔隙率为26%的3D打印样品被推荐用于使用该技术制造烧结芯，并测试Micro CT的准确性。
