Analysis Of Temperature Field Research Articles

Hydronic floor heating: Analysis of energy consumption, temperature, and velocity fields

Hydronic floor heating: Analysis of energy consumption, temperature, and velocity fields

Computational-Fluid-Dynamics-Based Optimization of Wavy-Slit Fin Geometry in Indoor Units of Air Conditioners Using Low-Global-Warming-Potential Refrigerants

This study explores the optimization of wavy-slit fins in the indoor units of air conditioners that use low-global-warming-potential refrigerants, with a focus on the interactions between slit length, width, and height. A response surface method was employed to analyze the trade-offs between thermal performance and pressure loss, and numerical optimization was performed using two objective functions: pumping power and volume goodness factor (Gv). The results demonstrated that optimizing the slits’ geometry significantly enhanced overall performance. For pumping power, a minimum point was observed near the design boundaries, which underscores the critical role of geometric interactions. The flow and temperature field analysis under fixed heat-duty conditions revealed substantial flow separation caused by the slits, enhanced mixing between the upper and lower surfaces, and a reduction of up to 2.05% in pumping power. In contrast, the Gv optimization model exhibited a more uniform flow, reducing flow separation beyond the pipe and improving the Gv by 1.85%, although it led to an increase in pumping power. These findings highlight the potential that tailored slit fin designs have to achieve a balanced enhancement in heat transfer and aerodynamic performance, offering valuable insights for the development of efficient, low-environmental-impact air conditioning systems.

Analysis of Temperature and Stress Fields in the Process of Hot-Rolled Strip Coiling

During the coiling process of a hot-rolled strip, with the increasing layers the temperature and stress distribution inside the coil constantly change and interact with each other. Due to the contact with the sleeve and the transition of the heat exchange state, it is inaccurate to consider the temperature of the whole coil as the coiling temperature set by the process requirement. Meanwhile, due to the periodic interlayer contact in the radial direction, the relation between stress and deformation is nonlinear. For the coiling process, it is difficult to consider the above factors using conventional methods. Therefore, an incremental model has been established to couple the temperature and stress of the coil. In order to obtain the mechanical properties of the strip and radial elastic modulus of the coil, tensile tests and laminated compression experiments are conducted at different temperatures. The effects of changes in strip thickness, coiling tension, and initial temperature of the sleeve on the stress and the temperature inside the coil are studied. Finally, by comparing the model results with measurements and analytical solutions, the effectiveness of the incremental coupled model is verified and the errors caused by the analytical method are analyzed.

Simulation Analysis of Temperature Field and Stress Field of Mass Concrete Under Different Construction Temperatures

In this study, the finite element analysis software MIDAS FEA NX was used to simulate and analyze the concrete, and the temperature regulation effect of phase change materials in concrete and its influence on crack resistance was discussed. A 1/8 concrete specimen model was constructed, and different ambient temperatures (5 °C to 35 °C) and concrete material parameters were set. Through simulation, it is found that phase change materials can effectively absorb environmental heat, maintain the temperature stability of concrete structures, and reduce the internal temperature peak. In addition, the addition of phase change materials can also reduce the temperature difference between the inside and outside of concrete, relieve the internal stress and improve the crack resistance of concrete. The results show that under different construction temperatures, the phase change concrete can quickly achieve the consistency of internal and external temperature and stress, reduce the cracking problem, and show good temperature regulation and crack resistance.

Numerical Analysis of Welding Heat Source Temperature Field

Numerical Analysis of Welding Heat Source Temperature Field

Hydrothermal Coupling Analysis of Frozen Soil Temperature Field in Stage of Pipe Roof Freezing Method

Taking the Sanya River Mouth Channel project as a case study, this research explores the minimum brine temperature required for the pipe-jacking freezing method during staged freezing. Based on the heat transfer theory of porous media, a three-dimensional model of the actual working conditions was established using COMSOL 6.1 finite element software. By adjusting the brine cooling scheme, the development and distribution patterns of the freezing curtain under different brine temperatures were analyzed. The results indicate that as the staged freezing brine temperature increases, the thickness of the freezing curtain decreases linearly, and the closure of isotherms is inhibited. When the brine temperature is −8 °C, the thickness of the freezing curtain meets the minimum requirement and effectively achieves the freezing effect under both low and high seepage flow conditions. Additionally, seepage significantly affects the formation of the freezing curtain, causing it to shift towards the direction of seepage, with the degree of shift becoming more pronounced as the seepage velocity increases. When the seepage velocity is so high that the thickness of the freezing curtain on one side is less than 2 m, the impact of seepage on the freezing curtain can be reduced by decreasing the hydraulic head difference in the freezing area or by increasing the arrangement of freezing pipes, thereby enhancing the freezing effect.

Measurement and analysis of fish pond water temperature field in summer based on fiber Grating string.

To solve the problems of low detection efficiency and inability to adapt to distributed measurement in traditional detection methods, a water temperature field detection system based on a fiber Bragg grating string was designed. In this system, six fiber Bragg gratings with different center wavelengths are connected in series on a single fiber optic cable based on wavelength division multiplexing technology. The fiber Bragg grating string is encapsulated in stainless steel tube and vertically fixed in the measured water body of the fish pond. The space division multiplexing technology is employed to collect information from multiple fiber Bragg grating strings. Water temperature measurement experiments were conducted in the summer pond environment. The experimental results show that the daily variation curve of temperature in each water layer of the fish pond is relatively smooth and approximates a cosine function with a 24-hour period. In summer, the daily average water temperature in the pond is no more than 1°C higher than the average air temperature. The difference between the maximum and the minimum water temperature is approximately 2°C. During the daytime, the temperature gradually decreases from the surface to the deeper water layers, whereas at night, the temperature variation among the water layers is minimal. As depth increases, the amplitude of the water temperature curve oscillations gradually decreases, exhibiting exponential decay. However, the peak time gradually lags behind. There is a correlation between the temperatures of the water layers in the fish pond, and the smaller the distance between the water layers, the stronger the correlation. The experimental results obtained in this study are highly significant for real-time services in aquatic planting and aquaculture. Additionally, this measurement method can provide valuable reference and guidance for measuring temperature fields in other fluids.

Temperature field analysis of an air-water composite cooling high-speed generator

Temperature field analysis of an air-water composite cooling high-speed generator

Temperature field analysis of motor with oil cooling based on CFD

Temperature field analysis of motor with oil cooling based on CFD

Integrated Prediction of Gas Metal Arc Welding Multi-Layer Welding Heat Cycle, Ferrite Fraction, and Joint Hardness of X80 Pipeline Steel

X80 pipeline steel is widely used in oil and gas pipelines because of its excellent strength, toughness, and corrosion resistance. It is welded via gas metal arc welding (GMAW), risking high cold crack sensitivities. There is a certain relationship between the joint hardness and cold crack sensitivity of welded joints; thus, predicting the joint hardness is necessary. Considering the inefficiency of welding experiments and the complexity of welding parameters, we designed a set of processes from temperature field analysis to microstructure prediction and finally hardness prediction. Firstly, we calculated the thermal cycle curve during welding through multi-layer welding numerical simulation using the finite element method (FEM). Afterwards, BP neural networks were used to predict the cooling rates in the temperature interval that ferrite nuclears and grows. Introducing the cooling rates to the Leblond function, the ferrite fraction of the joint was given. Based on the predicted ferrite fraction, mapping relationships between joint hardness and the joint ferrite fraction were built using BP neural networks. The results shows that the error during phase fraction prediction is less than 8%, and during joint hardness prediction, it is less than 5%.

Research on Temperature Field Analysis Method of High-Speed Bearing Chamber–Bearing System

The analysis of the temperature field of a high-speed bearing chamber–bearing system is very complex. We used the temperature field analysis method on a 40,000 rpm bearing chamber–bearing system by simulation, which builds on the finite volume method and introduces a decoupling method that separates fluid dynamics from the thermal analysis of the solid temperature field. Firstly, according to bearing operating conditions, the characteristics of the oil–air two-phase distribution in the bearing chamber are determined using the Volume of Fluid (VOF) method. The convective heat transfer boundary conditions derived from this analysis serve as the thermal boundary conditions for the subsequent thermal analysis. Secondly, considering the heat generation of the bearings and the thermal boundary conditions, a temperature field analysis model is formulated. The calculated results are found to be in close agreement with the actual test data, with an error of less than 10% under three operational conditions. Thirdly, the presented method to evaluate the temperature field of the bearing chamber–bearing system has not been studied in other published literature. Additionally, compared with the thermal fluid–structure interaction method, the method described in this paper can save 90.75% of calculation time, which significantly improves efficiency. Therefore, the above method is reliable for evaluating the temperature field of the bearing chamber–bearing system.

Experimental study and parametric analysis of temperature fields in corrugated web steel beams under solar radiation

The corrugated web steel beam (CWSB) is getting more and more applications in structural construction, while the concerns regarding the thermal effects caused by solar radiation on CWSB are limited. In this paper, a specimen was fabricated and instrumented with thermometers to obtain the temperature field characteristics of CWSB. Meanwhile, a numerical simulation method is established to describe its thermal behaviors under solar radiation. Comprehensive parametric studies are conducted to investigate the effects of environmental and geometrical parameters on the CWSB’s temperature field and the sensitivities of these parameters are subsequently determined. The solar radiation has the most obvious effects on the vertical temperature difference of CWSB, while its average temperatures are mainly dependent on the ambient air temperature. Additionally, comparison analysis has been carried to explore the differences in temperature field characteristics of steel beams having flat and corrugated webs. The discernible disparities in vertical temperature profiles of CWSB can be found among different sections, while the temperature profiles of the flat web steel beam are almost consistent at these sections. It hopes that the outcomes of this study can contribute to the temperature field of CWSB and provide some useful references for further investigations.

Analysis of temperature field in gun barrel under different firing numbers

Abstract To examine the impact of the temperature field created by the thermal shock of high-temperature propellant gas in the barrel during firing on the dependability of the gun’s lifespan, a finite element model of a gun barrel was created by using finite element software. Under single and continuous firing settings, the distribution law of the barrel temperature field was examined, and the convective heat transfer mechanism on the inner and outer walls of the barrel was simulated by using nonlinear transient thermodynamic theory. This establishes the groundwork for future investigations on the dependability of gun barrel life.

Rapid Analysis of Temperature Fields in Electronic Enclosures Based on the Finite Difference Thermal Resistance Network Method

Rapid Analysis of Temperature Fields in Electronic Enclosures Based on the Finite Difference Thermal Resistance Network Method

Meshing model and temperature field analysis of small module gear with curve configuration

This paper provides a new approach for the design of small module gear with curve configuration, and studies the meshing temperature rise of the generated tooth surface under dry running condition. To predict the meshing temperature of small module gear with curve configuration, the normal load and motion velocity of two contact points are analyzed based on vector mapping method, and the contact stress and contact deformation are obtained based on Hertzian contact theory. The frictional heat flux at different speed and torque is calculated as the heat source, and the convective heat transfer coefficient of tooth surfaces are calculated as the heat dissipation condition. Finite element model of temperature field of small module gear with curve configuration is established, and the meshing temperature field is obtained. Variation trend of the maximum steady-state temperature is in good agreement with the experimental test results. Simulation results of flash temperature also agree well with Blok theory. The results show the rotational speed and the torque are high, the meshing temperature rise of the gear pair will be high. The maximum temperature is distributed in the middle area of single tooth on the first contact trace of the gear.

Finite Element Numerical Simulation and Repair Process of Laser Cladding Repair of Surface Cracks on Mechanical Parts.

This study focuses on the planetary gear reducer and employs ANSYS 13.0 software to perform thermo-mechanical coupled simulations for the laser cladding repair process, aiming to address gear failure caused by cracks. The optimal theoretical repair parameters were determined based on temperature and stress field analyses, and performance testing of the cladding layer was conducted to validate the feasibility of the selected parameters. The results suggest that a laser power of 140 W and a scanning speed of 8 mm/s represent the optimal theoretical parameters for the laser cladding repair of the gear workpiece. Tensile strength tests revealed that the cladding layer's maximum tensile strength reached 1312.80 MPa, which was 1.22 times higher than that of the substrate material. Additionally, the wear resistance tests indicated that the wear loss of the cladding layer under the optimized parameters reduced from 9.3 mg for the base material to 0.5 mg, demonstrating excellent wear resistance. Thus, the mechanical properties of the cladding layer were significantly enhanced compared to the base material under these theoretical process parameters.

Dynamics of lead selenide films modification by laser annealing

The paper considers the modification of the structure and optical properties of chalcogenide films of lead selenide (PbSe) as a result of exposure to a continuous wave (CW) laser with 405 nm wavelength. The mechanisms of oxide layer formation and the accompanying changes in the optical properties of films during laser exposure were considered. Based on the measured reflection and transmission spectra of film regions modified by laser radiation with different exposure times (1–12 s), the extinction coefficient and refractive index were calculated. The study reveals significant modifications in the films' optical constants during the early stages of laser irradiation, leading to oxidation and melting, which are further stabilized by phase transitions. Additionally, temperature field analysis showed that the film's surface temperature in the laser spot's center is strongly influenced by the time-dependent absorption capacity, especially from the 3rd second of exposure onward.

Multifunctional Thermal Imaging Complex for Medical Diagnostics

Introduction. Recent developments in the field of thermal imaging technology and the accumulated experience in instrumental analysis of thermal processes in the patient’s body indicate the prospects of developing new medical thermal imaging systems (thermal imagers).Aim. Creation of a low-budget domestic thermal imaging system for medical diagnostics with expanded functionality.Materials and methods. The distribution of temperature over the surface of the human body depends on its internal state and external environment. For each person, this distribution has its own physiological characteristics, the study and interpretation of which can be significant for diagnosing specific pathologies or assessing the general (psychophysical) state of the patient. Analysis of temperature fields on the surface of the human body makes it possible to diagnose various pathological processes manifested in the form of local temperature changes in individual areas. The proposed method for thermal diagnostics involves measuring the temperature at each point of such an area simultaneously (statically) or over a period of time (dynamically). In comparison with conventional approaches, two thermal imaging sensors are used for this purpose. These include a small-sized matrix (thus being low cost) and a point sensor. Such a combination of sensors provides for the necessary discretization of the temperature field image of sufficiently large areas of the surface of the human body, when shooting from a distance significantly reduced compared to the conventional approach.Results. A conceptual electrical circuit and a layout of a modern thermal imaging system are developed. The advantages of the proposed thermal imager over similar devices are assessed. A method for recording and analyzing temperature in a certain point and temperature fields of both separate areas and large areas on the surface of the human body is proposed and tested.Conclusion. The conducted testing of a material model of the proposed thermal imaging system using the facilities of large medical institutions in St. Petersburg showed its wide functionality along with simplicity and convenience.

Research on the Geosynthetic-Encased Gravel Pile Composite Highway Foundation in Low-Temperature Stable Permafrost Regions

In low-temperature stable permafrost regions, both active and passive cooling measures are commonly employed to ensure the long-term stability of highway structures. However, despite adopting these measures, various types of structural issues caused by permafrost degradation remain prevalent in high-grade highways. This indicates that in addition to preventing permafrost melting, structural reinforcement of the foundation is still necessary. Based on the analysis of the long-term foundation temperature field and settlement using the finite element method, which was validated through an indoor top-down freeze–thaw cycle test, this paper explores, for the first time, the feasibility of applying geosynthetic-encased gravel pile composite highway foundations—previously commonly used for permafrost destruction—in low-temperature stable permafrost areas where permafrost protection is the primary principle. By analyzing the long-term temperature field, settlement behavior, and pile–soil stress ratios of permafrost foundations influenced by both the highway structure and composite foundation, it was found that when the pile diameter is 0.5 m, pile spacing is 2 m, and pile length is 11 m, the mean monthly ground temperature of the permafrost foundation will not be significantly affected. Therefore, the properly designed geosynthetic-encased gravel pile composite highway foundation can be adopted in low-temperature stable permafrost regions where permafrost protection, rather than destruction, is required.

Optimization of Hemolytic Performance for Blood Pump Based on Temperature Field Analysis and Three Control Strategies

Optimization of Hemolytic Performance for Blood Pump Based on Temperature Field Analysis and Three Control Strategies