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Boiling heat transfer, utilizing latent heat during phase change, has widely been used due to its high thermal efficiency and plays an important role in existing and next-generation cooling technologies. The most critical parameter in boiling heat transfer is critical heat flux (CHF), which represents the maximum heat flux a heated surface can sustain during boiling. CHF is primarily influenced by the wicking performance, which governs liquid supply to the surface. This study experimentally and numerically analyzed the wicking performance of micropillar structures at various temperatures (20–95 °C) using distilled water as the working fluid to provide fundamental data for CHF prediction. Infrared (IR) visualization was used to extract the wicking coefficient, and the experimental data were compared with computational fluid dynamics (CFD) simulations for validation. At room temperature (20 °C), the wicking coefficient increased with larger pillar diameters (D) and smaller gaps (G). Specifically, the highest roughness factor sample (D04G10, r = 2.51) exhibited a 117% higher wicking coefficient than the lowest roughness factor sample (D04G20, r = 1.51), attributed to enhanced capillary pressure and improved liquid supply. Additionally, for the same surface roughness factor, the wicking coefficient increased with temperature, showing a 49% rise at 95 °C compared to 20 °C due to reduced viscous resistance. CFD simulations showed strong agreement with experiments, with error within ±10%. These results confirm that the proposed numerical methodology is a reliable tool for predicting wicking performance near boiling temperatures.

A novel 3D printing route to fabricate continuous fiber reinforced metal matrix composite (CFRMMC) is proposed in this paper. It is distinguished from the 3D printing process of polymer matrix composite that utilizes the pressure inside the nozzle to combine the matrix with the fiber. This process combines the metallic matrix with the continuous fiber by utilizing the wetting and wicking performances of raw materials to form the compact internal structures and proper fiber-matrix interfaces. CF/Pb50Sn50 composites were printed with the Pb50Sn50 alloy wire and modified continuous carbon fiber. The mechanical properties of the composite specimens were studied, and the ultimate tensile strength reached 236.7 MPa, which was 7.1 times that of Pb50Sn50 alloy. The fracture and interfacial microstructure were investigated and analyzed. The relationships between mechanical properties and interfacial reactions were discussed. With the optimized process parameters, several composites parts were printed to demonstrate the advantages of low cost, short fabrication period and flexibility in fabrication of complex structures.

In this work, a self-made fabric testing instrument by aeolotropy hydroscopic method (TIH) under resistance theory was developed to track the movement of moisture across the fabrics. After the water transport performances of 11 pieces of Coolmax polyester knitted fabrics by the TIH and the classic wicking method were tested respectively, the accuracy and efficiency of TIH was discussed. Results show that wicking measurement is difficult to differentiate sweat transmitting properties differences in garment materials for the dynamic transfer of infinite quantity of liquid. The TIH method is an automatic and speedy test method, which can test the aeolotropy sweat transmitting properties for fabrics. The Lucas-Washburn equation does apply to TIH method, and it is feasible to substitute comprehensive wicking coefficients ( K C ) for sums of five sweat transmitting coefficients ( K Sum ) to evaluate the water transport performances for dress fabric in summer.

Paper-like materials have found widespread applications in various fields, especially recently emerging applications in biomedicine as paper-based devices, where liquid wicking behavior plays a significant role. Although tremendous experimental evidence has indicated that fluid control is a key technology to improve the performance of these paper-based devices, the underlying mechanisms of liquid wicking behavior in paper-like materials remain unclear. Numerical and mathematical techniques provide effective strategy and great potential in understanding the liquid flowing process in the complex fibrous structure of paper-like materials. In this review, we first present the basic physical process and key factors of liquid wicking behavior in paper-like materials. Furthermore, we review various macroscopic and mesoscopic mathematical models on fluid flow in porous materials, focusing on each model’s advantages and challenges, and summarize their related biomedical applications. The aims are to better understand the underlying mechanisms of liquid wicking behavior in paper-like materials through mathematical models and to provide guidance in the design and optimization of paper-based biomedical devices.

Liquid transporting and drying rate are two vital factors affecting the physiological comfort of sport garments. In this study, plated knitted fabrics produced with functional fiber yarns in the back of the knit (close to the body), combined with polypropylene or polyester in the face (outer surface) were tested in terms of their wicking behavior and drying rate capacity. Functional knitted fabrics were evaluated by vertical and horizontal wicking tests. The drying capability was assessed by drying rate tests under two different conditions, namely, at 20±2°C and 65±3% relative humidity and, in an oven, at 33±2°C, in order to simulate the human body temperature. The influence of the functional fiber used and that of the ground material, polyester or polypropylene, was analyzed and discussed.

Wicking geotextile is used to drain capillary as well as gravitational water out of soil. In order to investigate the effect of fabric parameter on the drainage performance of wicking geotextile, a series of soil column tests were conducted in this research. The test results showed that all the wicking geotextiles with different fabric parameters could drain water out of unsaturated clayed soil due to the existence of wicking fibers. The wicking geotextile with one wicking fibers yarn and fibers yarn space of 3 mm exhibited the best drainage performance and could reduce the soil water content by 11.31 % lower than its initial value of 18 %. With the same fabric parameter, large contact area between wicking fibers and soil was beneficial for the drainage performance of wicking geotextile. In addition, the fabric parameter had little effect on the effective drainage region of wicking geotextile, and the effective influence region of wicking geotextiles was more than 50 mm above and below the geotextile, respectively.

The wicking ability of the fabric is one of the most important parameters that affect the comfort of clothing. Silk is a natural long-fiber material, and researching the water-absorption properties of natural silk yarn helps in developing textile products with specific performance characteristics, thereby enhancing the competitiveness of textiles in the market. This research aims to analyze the wicking behavior of silk yarn simulating their interlaced conditions when they were woven. To investigate the effect of yarn twist and yarn fineness, 13 different silk yarns were examined in individual and interlaced scenarios. Results showed that both yarn twist and fineness affect the wicking performance, and the permeability and capillary hydraulic diameter were calculated. A comparison of experimental results and best theoretical fits according to Fries and Dryer’s proposed model. On the other hand, a good correlation was observed between the wicking length of single yarns and interlaced yarns. This suggests that the characteristics of single yarn can be potentially used for predicting the wicking behavior of woven textiles, where yarns form interlacements. This study can usher in innovations and enhancements that can benefit future virtual clothing design and real-world wear.

Active moisture control of wicking geotextiles is an effective way to prevent roadbed frost heave diseases. The performance of water conducting fibers determines the drainage function of the wicking geotextile. This study proposes a design method of the cross-sectional structure that synergistically consider drainage and mechanical properties in fibers. The circular or elliptical fiber profile and semicircular groove shape are first determined based on the maximization of the fiber cross-sectional specific surface area. Then, numerical simulation orthogonal experiments are conducted using COMSOL Multiphysics software to investigate the water conductivity and uniaxial tension of irregular fibers. The CRITIC weighted indicator of water conductivity to fiber volume ratio, tensile stress peak and fracture elongation is used as the analysis objects. The influence weights of fiber contour morphology, fiber size, groove number and groove area ratio on the weighted indicators are analyzed, and their optimal values are determined. The optimal “M”-shaped fiber is obtained, and the effectiveness of optimization design is verified through scanning electron microscopy and uniaxial tensile test. The “M”-shaped fiber is woven into the wicking geotextile, and geotextiles water conversion corporation test and drainage test of silty clay soil column is carried out. The test find that mass moisture content of the soil sample decreased by 4.73% within 8 days, which is 2.24% more than that of the staple fibers needling geotextile. This proves the effectiveness of “M”-shaped fibers and wicking geotextiles woven into them.

Metal foams have been widely used in heat pipes as wicking materials. The main issue with metal foams is the surface property capillary limit. In this paper, a chemical blackening process for creating a superhydrophilic surface on copper foams is studied with seven different NaOH and NaClO2 solution concentrations (1.5~4.5 mol/L), in which the microscopic morphology of the treated copper foam surface is analyzed by scanning electron microscopy. The capillary experiments are carried out to quantify the wicking characteristics of the treated copper foams and the results are compared with theoretical models. A the microscope is used to detect the flow stratification characteristics of the capillary rise process. The results show that the best wicking ability is obtained for the oxidation of copper foam using 3.5 mol/L of NaOH and NaClO2 solution. Gravity plays a major role in defining the permeability and effective pore radius, while the effect of evaporation can be ignored. The formation of a fluid stratified interface between the unsaturated and saturated zone results in capillary performance degradation. The current study is important for understanding the flow transport in porous materials.

Wicking geotextile (WG) is considered as a possible countermeasure to reduce water content in unsaturated soil. In this research, rainfall tests were carried out to verify the drainage performance of WG. And capillary rise tests were conducted to study the effect of WG on the prevention of capillary rise. Test results indicated that WG with good drainage performance could drain gravitational and capillary water out of kaolinite soil. For kaolinite soil column with water content of 12% and compaction degree of 90%, the whole process of capillary rise in soil column with a layer of WG was a typical two-stage mode, and the maximum capillary height was about 380 mm, which provided that the WG could work as a barrier to prevent capillary rise effectively. In addition, the total vertical influential regions of WG in kaolinite soil above and below the WG layer were 400 and 100 mm, respectively.