Tube Structure Research Articles

Crashworthiness design and enhanced energy absorption of multi-cell thin-walled circular tubes

In order to improve the crashworthiness and enhance the energy absorption capacity of thin-walled structures, a new multi-cell thin-walled circular tube was established by combining the advantages of type I (bending-dominant) and type II (tension-dominant) structures in this paper. The crush resistance and specific energy absorption (SEA) of multi-cell empty and multi-cell foam-filled tubes (MFTs) subjected to axial crushing loads were experimentally investigated. It was shown that due to the introduction of ribbed structures, the crush resistance and energy absorption efficiency of multi-cell empty tubes can be obviously enhanced. Filling the empty tube with foam, the peak force of foam filled thin-walled circular tube structure is improved distinctly. The MFTs have a higher crushing load efficiency and lower average loading fluctuation than the corresponding multi-cell empty tubes, which are mainly affected by the ribbed angles. With the increase in ribbed angles, the load-carrying capacity and the SEA of the MFTs can also be enhanced, but the undulation of the load-carrying capacity is simultaneously reduced. When the ribbed angle is more than 45°, the MFTs have better energy absorption and crushing load efficiency. Compared with a multi-cell empty tube, the SEA of the MFT increased by about 19%.

Gap defect and freeze-thaw cycles effects on mechanical characteristics of concrete-filled steel tube stub columns with experimental and theoretical investigation

As concrete-filled steel tube (CFST) structures become more prevalent in engineering, their durability garners significant attention. Mechanical characteristics of concrete-filled steel tube stub columns under the combined influence of gap defect and freeze-thaw cycles is presented with experimental and theoretical investigation in the paper. Twenty-six concrete-filled steel tube stub columns were designed to study the combined effects on failure mechanisms, axial compression-strain response, strength, and ductility. The experimental results indicate that as the number of freeze-thaw cycles and gap ratio increase, the deformation of the specimen increases and the deformation time advances. The specimen's strength and ductility are decreased by the combined effect of these factors. In the most severe cases, the specimen's overall strength and ductility are reduced by 29.4 % and 44.0 %, respectively. Subsequently, a finite element numerical model is established to parametrically analyze the concrete-filled steel tube stub column. Results show that the degree of restraint in the concrete-filled steel tube significantly influences the reduction in strength and ductility of the specimens. The stronger the restraining effect, the less the degradation of strength and ductility caused by the combined impact of the two factors. Therefore, it is crucial to effectively restrain the concrete within the concrete-filled steel tube to ensure structural safety and durability.

Crash resistance analysis and optimization of sponge like thin-walled pipes under multiple working conditions

The crashworthiness of bionic thin-walled structures has been the subject of considerable research interest. In this article, we emulate the bi-diagonal skeletal structure of deep-sea glass sponges and construct sponge-like multicellular thin-walled tubes (SLMTT) with a parameterized ratio of the number of two distinct single-celled organisms (CSS I and CSS II). Thin-walled sponge-like tubes of varying dimensions were manufactured using selective laser melting (SLM) technology. The crashworthiness of these structures was evaluated under axial compression, transverse compression, and three-point bending conditions through experimental and computational approaches, including parametric analyses of the inner and outer wall thicknesses. The results show that SLMTT I has better crashworthiness under the three working conditions, and the SEA of BLMESI is 40.9 and 26.13% higher than that of BLMESII. under transverse compression and three-point bending conditions, respectively. Finally, a multi-objective optimization design of SLMTT I under multiple operating conditions is carried out by the second generation of Non-dominated Sorting Genetic Algorithm (NSGA-II) with the aim of obtaining the ideal structure with maximum specific energy absorption and minimum initial peak crushing force. This study offers novel insights into the design of bionic energy-absorbing structures under diverse operational scenarios.

Modal testing and analysis of high-rise laminated timber building

To enhance the design and research work on dynamic characteristics of high-rise laminated timber buildings, this paper carried out a modal analysis study on one of the largest laminated timber buildings in China. The finite element calculating modal analysis was carried out using SAP2000 software, and the experimental modal analysis of the building was carried out via environmental excitation. The calculating modal results and the experimental modal results showed good agreement. The calculating modal frequency values were generally lower than the experimental modal frequency values. The natural frequencies obtained by the two methods appeared in the Y-direction first-order bending mode and had values of 2.03 and 2.5 Hz, respectively. The corresponding frequencies of the first-order torsional mode were 2.82 and 3.25 Hz, respectively. The distribution of the CLT core tube along the length direction of the building has an impact on the vibration mode. The six-story part shows the second-order bending form, while the four-story section only shows the first-order bending form. The above work provides a case study and reference for the simulation and modal analysis of high-rise laminated timber buildings, demonstrating the critical role of the core tube structure in such wooden buildings. This insight contributes to a better understanding of structural performance and design considerations in similar projects.

Simulation and Deformation Analysis of Construction Process of Large Eccentric Frame‐Core Tube Structure

ABSTRACTThe large eccentric frame‐core tube structure may generate nonnegligible horizontal deformation in the eccentric direction during the construction process, which should be given due attention. The construction process of a 388‐m‐high super high‐rise structure was simulated with the effects of concrete properties and construction processes. The reinforcement effect of steel bar in reinforced concrete shear wall and the hoop effect of steel tube in concrete filled steel tube (CFST) columns were considered by using the two‐cell simulation method, respectively. The accuracy of the finite element model was effectively verified based on the measured data under different construction process. The results show that the construction process has a large influence on both the vertical and horizontal deformation. The measures of construction leveling effectively reduce the vertical and horizontal deformation of super high‐rise structures, which is important for controlling the structural deformation. The proportion of creep‐shrinkage deformation in the total deformation is large. In this case, the proportion of creep‐shrinkage deformation in the shear wall is 45% to 50%, whereas it is about 30% in the frame columns. The eccentricity caused by floor slab gravity will be mitigated if the construction of the frame slab lags behind the construction of the steel frame, which is beneficial to the control of the horizontal structural deformation. After construction completion, the deformation caused by nonload factors is limited compared to the deformation caused by live loads.

Study on the thermal storage properties of a spiral tube heat storage tank based on numerical analysis

IntroductionThe spiral tube heat storage tank is a highly efficient device designed for storing and releasing heat, utilizing a spiral tube structure. Its key advantages include efficiency, reliability, and flexibility, making it suitable for a wide range of conditions, from high temperatures and pressures to low temperatures and high vacuums.MethodsThis study aims to analyze phase change heat storage in spiral tube heat storage tanks using numerical simulation.ResultsIt explores the impact of varying water supply temperatures on heat transfer efficiency and the melting behavior of phase change materials within the tanks. Proposed enhancements, informed by numerical simulation results, seek to improve heat transfer efficiency. Simulation findings indicate that charging efficiency rises with increased temperature differentials, akin to sleeve-type heat exchangers.DiscussionCalculations suggest faster melting of phase change materials at the central position of the tank’s spiral tube, with slower melting near the vessel wall. Consequently, reducing the number of spiral tubes in the middle is suggested for future structural optimization.

Effects of SiO2-coated CNTs on the directional formation of SiC whiskers and improvement in the ablative resistance of polymer-matrix composites

As the development of hypersonic aerospace technology progresses, greater challenges are presented for solid rocket motors (SRMs) thermal protection, and the ablation performance of insulation materials needs to be further improved. Carbon nanotubes (CNTs) as a new type of reinforcing nano-filler, readily react with the oxidative components in the working gas during SRMs operation, limiting their excellent performance. In this study, we propose to coat the commonly used reinforcing filler, SiO2, on the surface of CNTs to suppress their susceptibility to oxidation and investigate the effects of adding CNTs, SiO2, and CNTs@SiO2 to the matrix on material properties. The results show that the addition of CNTs@SiO2 significantly improves the ablation resistance of the insulation material, with the linear ablation rate of M-@SiO2-2 being 56 % lower than that of M-SiO2-2. Based on the analysis of the material's antioxidation performance and the strength of the resulting char layer after ablation, the reasons for the improvement of ablation performance are discussed. By conducting high-temperature tube furnace tests, the composition and structure of the char layer at different temperatures are studied, and it is found that CNTs in the CNTs@SiO2 formulation can directly provide the carbon source required for the carbon thermal reduction reaction, promoting the directional growth of SiC whiskers. Based on these findings, an ablation mechanism is proposed.

Seismic fragility assessment of eccentric gravity column-core tube structures subjected to pulse-like ground motions

The effects of pulse-like ground motion and structural eccentricity on the seismic fragility and anti-collapse behavior of the new gravity column-core tube structural system are investigated. Numerical models of the gravity column-core tube structure are first established employing the CANNY program and validated against the shaking table test results. Subsequently, reference symmetric gravity column-core tube structures with 10-, 20- and 30-stories are designed, and then their eccentric structures are established by changing the nodal mass distribution. Ten pulse-like and ten corresponding non-pulse-like ground motion records are selected as the seismic excitations. The seismic fragility and anti-collapse analysis of these eccentric structures are conducted. The results show that the pulse-like ground motion significantly affects the seismic response and fragility of the gravity column-core tube structures, with an apparently higher probability of exceeding the limit states (Pf) for the pulse cases than those for the non-pulse cases. With increasing eccentricity, the Pf shows an increasing trend. Besides, both the pulse-like ground motion and the increase of eccentricity lead to a decline in structural anti-collapse capacity. The results are expected to provide a reference for the seismic design of the new gravity column-core tube structures.

Machine learning-based residual drift prediction of concrete-filled steel tube columns under earthquake loads

This study introduces a machine learning (ML) model for predicting the residual (permanent) drift in concrete-filled steel tube (CFT) structures exposed to excessive loads. The relationship between the residual drift and design parameters of the CFT column was established through the adaptation of six distinct ML models. The accuracy of the proposed model was evaluated by comparing its predictions with the results derived from existing numerical models and code provisions. The proposed ML model surpasses existing residual drift prediction models by at least 4% in terms of R-squared value. To evaluate the effectiveness of the model, a nonlinear dynamic analysis of a three-story, three-bay CFT moment-resisting frame subjected to 44 ground motions was conducted using a numerical model. Additionally, two modified frame models were considered to investigate the influence of frame configuration on the performance of the ML model. Subsequently, the residual inter-story drift ratio derived from the seismic analysis using the numerical model was compared with the results obtained from the ML predictive model and code provisions. The proposed ML model exhibited greater accuracy in predicting the residual inter-story drift ratio than the code provisions when applied to the results of numerical analyses performed for weak-column strong-beam frames. The ML model showed a positive R-squared value, whereas the code provisions yielded a lower R-squared value. In turn, the ML model applied to the strong-column weak-beam moment-resisting frames tended to overestimate the residual inter-story drift ratio, with a ratio of the predicted value to the value obtained from the analysis equal to 3.5.

Research on concrete-filled square CFRP steel tube under compressive-torsional hysteresis loading

Concrete-filled CFRP steel tube structures are presently employed on extensively in various engineering practices. This study examines the mechanical performance of concrete-filled square CFRP steel tubes under compressive-torsional hysteresis loads. Through the analysis of nine specimens, the research focuses on failure modes, torque–angle (T–θ) behavior, triaxial strain, and the synergistic effects of the steel tube and CFRP during cyclic loading. A numerical simulation method is initially introduced based on the test data to predict the actions of concrete-filled CFRP steel tube compressive-torsional specimens under hysteresis loading. This method is subsequently verified by contrasting it with the outcomes from representative experiments. In addition, the stress distribution of each material during the entire loading process of the sample is examined. Finally, using data from experiments and finite elements, combined with the trilinear model, a hysteretic model under compressive-torsional hysteresis stresses has been established for square CFRP steel tube filled with concrete. The calculated outcomes of the developed finite element model closely align with those of the hysteretic model.

Research on oil well production analysis based on long-term slow-release tracer

Abstract Downhole monitoring the production profile is crucial for the development of oil and gas reservoirs. Currently, the commonly methods for monitoring the production profile include logging tools and using tracer monitoring. The tracer monitoring method is more popular in oil field operations due to its wide applicability, simple process, low cost, low risk, and long monitoring time. However, compared to traditional logging tool monitoring methods, tracer monitoring has drawbacks such as data lag, difficulty in downhole installation, and unstable long-term effects. Bohai Oilfield has developed a new type of solid tracer and solved the problem of downhole installation by improving the structure of the downhole screen tube. This tracer uses polymer material as the skeleton. After entering the designated position, the internal tracer can slowly diffuse into the solvent through the pores in the skeleton, achieving slow release and long-term monitoring of the production profile of the oil well. In 2023, this new type was first applied in the D6 well in Bohai Sea, and a half month stable production stage liquid production profile was obtained through sampling. The monitoring results showed that: (1) Solid slow-release tracer monitoring technology can continuously obtain production layer information in complex environments and can be used for short-term rapid water exploration and long-term water production monitoring, identifying water breakthrough time and main water breakthrough location, (2) The distance between water injection well and D6 production wells is small, and the water injection volume in the injection wells is large. The tracer monitoring results show that there is a certain degree of water flooding in all 6 sections of each test layer, (3) The first test layer is the main liquid production section, the first and sixth test layers are the main oil production sections, and the first and second test layers are the main water production sections. The research results can determine the oil and water production situation of each section of oil well, identify the water breakthrough time and water outlet position, and provide a basis for the next development adjustment.

Axial behavior variation of 72-story concrete-filled steel tubes with different joint connections due to interface debonding considering long-term deformation of concrete core

Long-term concrete deformation including shrinkage and creep occurring seriously threats the longevity, safety and serviceability of concrete-filled steel tube (CFST) structures. In this study, numerical simulation on the variation of axial behavior of 72-story CFST structures with different joint connection details due to interface debonding considering shrinkage and creep of concrete core is carried out. Three connection details including connections with inner horizonal diaphragms only, two-direction through-beams only, and inner horizontal diaphragms combined with two-direction through-beam, are considered, respectively. Vertical loading from floors is treated as centralized vertical force applied on steel tube directly. The shrinkage of concrete core is simulated by decreasing concrete temperature. A cohesive constitutive law and a Coulomb friction model are employed to describe the interface behavior in tangential direction before and after debonding, respectively. The interaction between concrete core and steel tube in normal direction is treated as a hard contact. The concrete plastic-damage (CPD) constitutive model is used for concrete core and a plastic constitutive law is employed for the steel tube. The initiation of the interface debonding between steel tube, H-shaped steel beam flanges, inner diaphragms and concrete, the variation of the force transfer path, stress redistribution, steel tube yielding and the final failure are described in detail. Results show that the axial load-carrying capacity of each CFST structure has a decrease of 26-28% when compared with that determined by the current design code where the confinement effect is considered, and a decrease of 9-10% when compared with that determined by the current design code where the confinement effect of steel tube is not considered. Moreover, the axial stiffness decreases to 76-78% of their theoretical values when debonding is not considered. Numerical results show that the interface debonding negatively affects the long-term axial load-carrying capacity and stiffness obviously, which has not been considered in current design codes. Some comments on the design of CFST members are proposed based on the numerical simulation results.

Research and Application of Intelligent Well Completion Technology in Offshore Oilfield

Abstract The reservoirs in Bohai oilfield were mainly composed of unconsolidated sandstone. A single multi-layer gravel packing operation could greatly reduce the packing operation time and improve the operation efficiency. However, the conventional tools were limited by the double-layer central tube structure, which resulted in large packing friction and high pressure consumption due to its small annular area, which limited the limit operation length and displacement. In order to solve this problem, we independently developed a double-layer screen tube one-time multi-layer fracturing packing tool, innovatively set up production interlayer in the screen pipe, formed a bypass diversion screen pipe system, so as to reduce the downward entry of one layer of central pipe during filling, simplify the structure of the filling string, and greatly reduce the friction of the string. The results showed that the limit packing length and displacement were 1200m and 45bpm respectively, which were 300% and 50% higher than the traditional packing tools, and the operation range of the tools was improved. The safety and efficiency of double screen fracturing and filling operation were ensured by innovating the quick connection method of double screen pipe, fast pressure test tool and expanding switch tool of oil pipe. The application in well LX has realized the purpose of sand control by five layers filling in one time. The packing length was more than 400 m. Combined with the problems in field operation, it had been applied in 5 areas The improvement suggestions of the tool are put forward. The double screen pipe one-time multi-layer fracturing packing tool and its supporting technology realized the ideal packing parameter requirements of low pump pressure and high return velocity. It could be widely used in sand control operation of multi-layer gravel packing fracturing in large-span perforation section in the future, which greatly improved the operation efficiency and has good economic benefits and promotion value.

Mechanical behavior of water ingress process for the locally damaged submerged floating tunnel and its interpretation: A full-length experimental study

The submerged floating tunnel (SFT) is an innovative transportation solution for traversing deep-water regions. However, local damage and subsequent water ingress pose significant threats to the structural integrity and safety of SFTs. This critical issue has been unexplored in the field. This study addresses this gap by presenting a comprehensive experimental investigation using a full-length physical model of the SFT. The dynamic response and failure mechanisms caused by water ingress within the SFT tube, influenced by various factors such as immersion depth, damaged opening angle, damaged opening area, and external connectivity, are systematically investigated. The results indicate that the failure of the anchor cable and tube structure of the SFT progresses through three stages after water ingress occurs in the damaged SFT. It is observed that damage closer to the bottom of the tube reduces the risk of failure in the mooring system. Notably, air pressure is a critical factor influencing the water ingress into the tube body. The attenuation of cable tension and tube deformation is significantly slower when the internal air is isolated from the external environment. The proposed novel structural sealing segmental disaster prevention design scheme substantially mitigates the risk of structural damage under compromised conditions and water ingress. This study provides valuable insights into enhancing disaster prevention strategies for SFTs and advances the understanding of their mechanical behavior in response to damage and water ingress.

Plasmon and N-vacancy synergistically enhanced tubular carbon nitride-based S-scheme heterojunction photocatalyst with one stone five birds function: Pathways, DFT calculation and mechanism insight

From the perspectives of innovation and broad-spectrum, tubular carbon nitride-based photocatalyst, viz., Ag/AgI/g-C3N4 S-scheme heterojunction photocatalyst, with enhancement of nitrogen vacancy and localized surface plasmon resonance (LSPR) effect is reasonably devised and manufactured via combining hydrothermal, calcination and photo-reduction techniques. The optimal specimen displays high photocatalytic activity in removal of dyes (such as crystalline violet, 100.00 %/60 min), antibiotics (such as levofloxacin, 88.72 %/50 min) and Cr6+ (100.00 %, 30 min), photocatalytic hydrogen evolution (1023.3 μmol h−1 g−1) and H2O2 generation (866.2 μmol h−1 g−1), achieving broad-spectrum natures, viz., realizing the function of “one stone five birds”. The broad-spectrum natures are attributed to the synergisms of nitrogen vacancy, LSPR effect of Ag, hollow tube structure and S-scheme heterojunction, which facilitate the separation and migration of photo-generated carriers and inject “hot electrons” generated by Ag into the conduction band of Ag/AgI/g-C3N4, increase the specific surface area and broaden the spectral response range. Further, the degraded intermediates of crystalline violet and levofloxacin and possible degradation pathways are rationally advanced by the aid of LCMS spectra, and synergistically enhanced photocatalytic mechanism of Ag/AgI/g-C3N4 hollow tube S-scheme heterojunction is confirmed based upon a series of sound experiments, fs-TA spectra, in-situ XPS and DFT calculation, etc.

A Motion Planner Based on Mask-D3QN of Quadruped Robot Motion for Steam Generator.

Crawling robots are the focus of intelligent inspection research, and the main feature of this type of robot is the flexibility of in-plane attitude adjustment. The crawling robot HIT_Spibot is a new type of steam generator heat transfer tube inspection robot with a unique mobility capability different from traditional quadrupedal robots. This paper introduces a hierarchical motion planning approach for HIT_Spibot, aiming to achieve efficient and agile maneuverability. The proposed method integrates three distinct planners to handle complex motion tasks: a nonlinear optimization-based base motion planner, a TOPSIS-based base orientation planner, and a Mask-D3QN (MD3QN) algorithm-based gait motion planner. Initially, the robot's base and foot workspace were delineated through envelope analysis, followed by trajectory computation using Larangian methods. Subsequently, the TOPSIS algorithm was employed to establish an evaluation framework conducive to foundational turning planning. Finally, the MD3QN algorithm trained foot-points to facilitate robot movement along predefined paths. Experimental results demonstrated the method's adaptability across diverse tube structures, showcasing robust performance even in environments with random obstacles. Compared to the D3QN algorithm, MD3QN achieved a 100% success rate, enhanced average overall scores by 6.27%, reduced average stride lengths by 39.04%, and attained a stability rate of 58.02%. These results not only validate the effectiveness and practicality of the method but also showcase the significant potential of HIT_Spibot in the field of industrial inspection.

Monte Carlo dosimetry study of newly designed shielded applicators for intensity modulated brachytherapy of cervical and vaginal cancers

IntroductionThe utilization of metal shields in intensity-modulated brachytherapy (IMBT) enables the modulation of the dose, resulting in improved conformance to the tumor while simultaneously reducing the doses to organs at risk (OARs). Utilizing higher-energy sources like 60Co in IMBT for cervical and vaginal cancers has consistently posed challenges. This study evaluates the dosimetric aspects of modified applicators designed for IMBT using 60Co and 192Ir sources.Materials and MethodsGATE, a Geant4-based simulation code, was utilized to model and simulate four distinct applicators. The clinical applicators were redesigned to place the structure of the source tube and the shield while keeping the general characteristics unchanged. These shields were evaluated by calculating transmission factors (TFs) and the dose homogeneities were also determined.ResultTransmission factors for the IMBT technique in redesigned intrauterine applicators and tungsten shields for iridium and cobalt sources were at least 12.8 and 65.4%, and these values were obtained for the intravaginal applicator at 0.2 and 7.0%, respectively. The dose homogeneities for all combinations of radionuclide-shield were within a 15% range of the non-IMBT applicators.ConclusionThis study has quantitatively evaluated the dosimetric effect of tungsten shields in the IMBT technique for cervical and vaginal cancer using cobalt sources. 192Ir compared to 60Co resulted in higher effectiveness for the designed intrauterine and intravaginal shields. while implementing tungsten shields in the redesigned applicators against the 60Co source may not offer complete protection, it does show promising results in reducing the dose to organs at risk.

The Analysis of Cultural Literacy in Ethnomathematics used by The Animaker Website at The Kramat Buyut Trusmi Mosque

Ethnomatematics is mathematics that connects mathematical concepts with elements of culture or everyday life. This research aims to identify and describe ethnomathematics in the Kramat Buyut Trusmi Mosque building as a learning resource assisted by the animaker website. Animaker is a medium for creating explanatory videos and presentations. The research carried qualitative research with an ethnographic approach where this approach leads to observation and has a role as part of field research. Researcher played the role of planning, collecting information, documenting and also analyzing information or data, who will then choose anyone as a source of data or information. Data analysis through data collection techniques, data reduction, data presentation, and also drawing conclusions. The results of the research showed that several buildings in the Kramat Buyut Trusmi Mosque include Gapura Kori Agung which is an example of a building that contains elements of spatial plane geometry such as a rectangular pyramid on the roof of the building, a tube structure found in a water barrel located not far from the door gate, in the gate there are also geometric elements of transformation such as reflection or mirroring.

Crashworthiness design of additively manufactured lattice-reinforced sandwich tube

A body-centered cubic lattice reinforced sandwich tube structure is designed, and the specimens are prepared using Selective laser melting (SLM) technology with integrated printing and split assembly. The effects of inner and outer wall thickness, loading rate and interaction on the deformation pattern and crashworthiness of the structures were investigated through experiments and numerical simulations. The results indicate that when subjected to axial compression, the integrated printed lattice reinforced sandwich tube (IPLT) forms more folds, and its specific energy absorption increases by 17.61% in comparison to the split assembly lattice filled sandwich tube (SALT). Under transverse compression, the integrated printed lattice reinforced sandwich tube showed no separation of the lattice from the thin-walled tube, and the specific energy absorption increased by 103.78% compared with the split assembly structure. It is noteworthy that the specific energy absorption of the designed reinforced sandwich tube under axial compression (transverse compression) increased by 294.83% (1233.95%) compared with the outer thin-walled tubes. This paper provides new ideas for the production of energy-absorbing components that are light-weight and have good crashworthiness.

Experimental study on the pool boiling heat transfer of R134a outside various enhanced tubes

The paper aims to experimentally study the pool boiling heat transfer properties of R134a outside various enhanced tubes under saturation temperatures ranged from 3 to 40 °C and heat fluxes of 5.5∼76.5 kW·m-2. One smooth tube and three micro-fin tubes were selected as the tested tube. Based on the experimental results, it can be found that the pool boiling heat transfer coefficient increases firstly and decreases later with increasing heat flux, but saturation temperature and water velocity have little effect on the heat transfer coefficient. Under the same experimental conditions, refrigerant thermal resistance ratio is greater than 0.5 during the heat transfer process. The micro-fin facilitates the bubble nucleation with the heat transfer enhancement ratio varying in the range of 2.08∼4.59. Moreover, the experimental values are compared with the calculated values of three existing correlations for the pool boiling heat transfer coefficient. The experimental variables, which mainly includes saturation temperature, heat flux and tube structure, have great influences on the correlation accuracy. Finally, to eliminate the influence of the experimental variable, a new correlation was proposed by introducing ratio of fin height to outer diameter of the tested tube. After the further verification, the proposed correlation can predict the heat transfer coefficient with the mean deviation of less than 10%.