Measurement Of Temperature Distribution Research Articles

An empirical study for the correction of the thermal parameters of a Li–Po battery with carbon-graphene-silicone coatings

The large use of batteries as energy storage systems for stationary applications and mobility has increased the concern about some limitations and issues, particularly in thermal management. This work presents the effect of coatings for battery heat dissipation with different conductivity, varying from 0.67 to 6 W/mK, and thicknesses, from 0.5 to 1 mm. The investigation is performed during the discharge phase with two current ratings, 0.5C and 1C, that correspond to 1.65 A and 3.3 A, respectively. Measurements of 2D temperature distribution are performed with thermal imaging while local data are collected with a thermocouple. The influence of the battery coatings is analyzed in terms of the temperature gradient, highlighting a lower increment in surface temperature for coatings with high conductivity. Then, the correction of the thermal parameters as the convective heat transfer coefficient and the specific heat capacity is considered for a reliable temperature prediction. In particular, the evaluation of these unknown parameters is performed simultaneously and in non-stationary conditions using two theoretical tools. The convective heat transfer coefficient must be changed from 14 to 17 W/m2K and the specific heat capacity from 2900 to 3500 J/kgK to model the battery behavior with the coatings. The methods applied for this evaluation are the finite-difference method and Newton's cooling law. A reverse approach is applied, using the experimental data to find the thermal parameters, only one method suits for this application. The predictions of the finite difference method have a lower standard deviation than the Newton's law model, 10% versus 50%. Moreover, it is more robust for the test cases with high noise-to-signal ratio and it is sensitive to the coating material and thickness. The presented results highlight that the method that best fits these applications requires characteristics such as good reliability, higher flexibility, and low sensitivity to experimental data fluctuations. The parameters estimated with the finite-difference method are also validated in real driving conditions, representative of a homologation test cycle. In this case, the battery temperature is still well predicted, showing that underestimating the model temperature of only 1.5% produces the best fit for the experimental data.

Temperature Distribution Monitoring on Blood Bank Chamber Using Android Application on Mobile Phone

Blood cold chain is a mandatory requirement of blood donation procedures to protect blood from bacterial contamination and to extend the shelf life of blood. Blood bank as a storage medium for blood bags requires a temperature between 2℃-6℃ on average. However, in general, blood banks only have 1 cold temperature distribution point, which is feared that the spread of cold temperatures in the compartment will be different at each point. For this reason, the researcher intended to design a blood bank temperature distribution monitoring device consisting of 7 measurement points. In this case, temperature sensor readings at each point are displayed wirelessly to smartphone devices using the Blynk platform and are also on a 3.5-inch TFT screen. The measurement data were then stored on the SD card memory so that the level of temperature fluctuations in the blood bank compartment can be analyzed during use. The module was also equipped with an alarm warning on the module and the Blynk application if the temperature is out of the normal temperature range (2℃-6℃). Before being used for measuring temperature distribution, the device made was compared with the standard Fluke DPM4 tester, in which the highest error obtained was 2.08% at T1, 1.58% at T2, -2.73% at T3, 1,61% at T4, -1.07% at T5, -0.06% at T6, and -2.32% at T7. After being compared with standard equipment, the device was used to measure the temperature spread in the Kirsch brand blood bank and the average temperature obtained was 3.56℃ at T1, 3.58℃ at T2, 3.73℃ at T3, 3.57℃ at T4, 3.67℃ at T5, 3.63℃ at T6, and 3.72℃ at T7. Based on the analysis results, the blood bank monitoring device can be used to measure the temperature spread in the blood bank compartment at 7 measurement points. Furthermore, temperature readings can be monitored wirelessly and remotely. It is hoped that this research can further help laboratory personnel at the Blood Transfusion Unit to monitor and evaluate the level of temperature spread in the blood bank compartment and prevent early damage to blood components.

Measurement and evaluation of ambient temperature distribution in Mubi town, Adamawa State, Nigeria

This paper is based on measurement of ambient (air) temperature distribution in Lamurde, Mubi South local government area, Nigeria. HTC-2 digital LCD thermometer and hygrometer electronic meter manufactured by Shenzhen Oway Technology Co. Limited Guangdong, China was used to collect data in the study area and compared with the National Aeronautics and Space Administrative (NASA) values. The results of the research revealed the maximum air temperature of 29.30oC against 33.70oC (NASA). Instat 3 and Microsoft Excel statistical package were used to analyze the data obtained. The results of T-test revealed p value of 0.0009 which is considered as extremely significant at 95% confidence interval and F-test showed that f (0.08) ≤ F (0.42) which revealed that there is no significant difference between the two data because it has 75% correlation coefficient. The study concluded that the data obtained could be used for research purpose and recommended that other sophisticated equipment should be used to validate the data.

RGB color camera for dynamical measurements of high temperature distribution on a surface of the heated solid

In this report we describe a fast 3-color method of the measurement of temperature distributions on a surface of a heated solid using a RGB color camera with a high frame rate (100 images per second). Statistical error the RGB method is not high, and do not exceed around 5.5% which is surprising taking in to account the number of the measurements at each pixel. Comparison of the results of the temperature measurements on a tungsten plate heated by infra-red laser radiation and conducted with this technique and those obtained with the acousto-optical tunable filter technique demonstrate that error of the temperature measured by 3-color method is only two times as high as that of the tandem acousto-optic filter technique method.

Simultaneous Measurement of Strain and Temperature Distributions Using Optical Fibers with Different GeO2 and B2O3 Doping.

Compensating for the effects of temperature is a crucial issue in structural health monitoring when using optical fiber sensors. This study focused on the change in sensitivity due to differences in GeO2 and B2O3 doping and then verified the accuracy when measuring the strain and temperature distributions simultaneously. Four types of optical fiber sensors were utilized to measure the strain and temperature in four-point bending tests, and the best combination of the sensors resulted in strain and temperature errors of 28.4 μϵ and 1.52 °C, respectively. Based on the results obtained from the four-point bending tests, we discussed the error factors via an error propagation analysis. The results of the error propagation analysis agreed well with the experimental results, thus indicating the effectiveness of the analysis as a method for verifying accuracy and error factors.

Lock-in Thermography Using Diamond Quantum Sensors

Precise measurement of temperature distribution and thermal behavior in microscopic regions is critical in many research fields. We demonstrate lock-in thermography using nitrogen-vacancy centers in diamond nanoparticles. We successfully visualize thermal diffusion in glass coverslip and Teflon with micrometer resolution and deduce their thermal diffusivity. By spreading diamond nanoparticles over the sample surface, temperature variation can be measured directly without any physical contact, such as lead wires, making it possible to visualize the micrometer-scale thermal behavior of various materials.

A real-time cutting temperature monitoring of tool in peripheral milling based on wireless transmission

In the milling process, the milling heat generated by the interaction between the tool, the workpiece, and the chips has a significant impact on the chip formation mechanism, tool wear mechanism, tool life, surface quality and so on. Therefore, it is of great significance to explore the heat and temperature distribution in milling. In the method of measuring temperature distribution, continuous measurement of transient temperature is the main method to study the temperature change during the rotation of the tool. During the rotation of the tool, the conventional temperature measurement method will cause stranding due to the linkage of the tool and the worktable, and cannot achieve continuous temperature measurement during the rotation. Therefore, the continuous measurement technology of tool transient temperature based on wireless transmission has been widely used, such as Bluetooth, wifi, radio frequency and so on. However, the current continuous measurement technology of tool transient temperature based on wireless transmission usually cannot provide sufficient bandwidth (low sampling rate). In order to narrow this gap, a high sampling rate continuous tool transient temperature measurement platform is needed to develop. Therefore, the milling temperature of the peripheral milling tool is studied from two aspects: theoretical research and experimental verification. The specific research process is: take the milling tool (insert) as the research object, and elaborate on the milling temperature from several aspects such as temperature field modeling and transient temperature continuous measurement key technology, experimental research, and influencing factors. Manual thermocouple and wireless transmission technology continuously measure the transient temperature of tool peripheral milling with high sampling rate. A real-time temperature monitoring of tool in peripheral milling based on wireless transmission is verified in the paper.

Applications of distributed fiber Bragg gratings to the measurements of in-tube fluid temperature distribution

The temperature distribution information of the two-phase fluid inside a tube can effectively reflect the heat transfer of the fluid, which is the key information in the study of the heat transfer of flowing fluid in a tube. This article aims to develop a method for measuring the temperature distribution of fluid inside a tube based on distributed fiber Bragg gratings (DFBGs). It is more convenient than traditional measurement methods using thermocouples that are impossible to be installed to the inner tube of a double tube heat exchanger. By using a stainless steel seamless tube, ϕ1.0 × 0.2 mm in size, and a hose to seal and protect the optical fiber with Bragg grating sensors inside, we successfully shielding the stress effects from the thermal effects, and also enhance the durability of the fiber. Since the seal leads to extra thermal resistance to the DFBGs, obtaining the response performance of the sealed DFBGs to a temperature change is essential for reliable applications. The performance characterization shows that the temperature measurement repeatability of the sealed DFBGs is within 0.2 °C for a period up to 35 months. The time constants of the DFBGs are not longer than 0.25 s, capable of measuring the temperature oscillations with frequency less than 2 Hz. Comparison with commercial thermocouples supports the feasibility and the reliability that the sealed DFBGs can be used as temperature sensors. To obtain the equivalent thermal conductivity between the tube that sealed the fiber and the fiber, κ¯air, the response to a temperature jump was also calculated based on a simplified model, which can comprehensively reflect the heat transfer of the air inside the sealed tube and provide the reference for design optimization of a sealed FBG for dynamic measurements. Finally, the capillary tube with sealed DFBGs was placed in the condenser tube of a two-phase circulation loop to exhibit the feasibility of the steady and dynamic temperature distribution measurements of the fluid inside a tube.

Multi-Spectral Camera for Dynamic Measurements of High Temperature Distribution over Solid-Body Surfaces

The new method of quick temperature surface distribution measurement based on eight-colour video camera is presented. Measurement frequency is 80 Hz. The mathematical apparatus is developed for determination of temperature distribution in the camera field of view without using radiation capacity data. Statistical temperature measurement error is 10 % at 1170 K and 3 % at 1500 K. It is demonstrated that the multi-spectral measurement method is viable and allows us to obtain temperature distributions of objects with unknown composition.

Rough contact surface reconstruction based on A mechanical-thermal contact model

Direct observation and measurement of stress and temperature distributions at contact interface is a challenge due to the randomness and complexity of surfaces, as well as the interface is always opaque. In this paper, the random contact process is characterized based on the real contact volume, and then the mechanical-thermal contact theory is established, which reveals the interaction mechanism between contact force and thermal resistance. Then, a reconstruction method of interface topography, contact stress and temperature distribution is established based on this model combination with modified W-M fractal function, which provides a visual evaluation method for the concealed interface performance of complex engineering structures. The proposed indirect method of interface contact characteristics is expected to be applied in the detection and evaluation of complex engineering structures.

Single Crystal Growth of 4‐Aminobenzophenone (ABP) by Solution and Seeded Czochralski Pulling Techniques for Second Harmonic Generation Applications

AbstractHighly efficient 4‐aminobenzophenone (ABP) single crystals are grown from melt by employing the seeded Czochralski pulling technique for second harmonic generation (SHG) applications. The as‐grown seed crystals from solution with dominant (100) and (001) facets are utilized to trigger the directional solidification. For successive growth, initial measurements of the furnace temperature distribution, heat flow structure, and solidification temperature of ABP in correlation with differential scanning calorimetry (DSC) analysis are made. The controlled diffusion is ensured by monitoring the interfacial layer between the melt and the growing crystal and is maintained by optimizing the melt temperature and pulling and rotation rates. Color change of the melt due to thermal‐oxidation is prevented by appropriate control of the growth environment. A slow and steady growth rate affirms the good quality of the ABP single crystal. The anisotropic growth behavior of ABP from solution and melt is reported. Internal molecular structure, crystalline purity, molecular vibrational modes, optical transmission, and thermal behavior are studied using single crystal and powder X‐ray diffraction, FTIR, UV–vis–NIR and DSC analyses. The obtained higher SHG efficiency of the grown ABP in comparison with that of the organic and inorganic standards urea and KDP reveals its suitability for SHG applications.

Dual-IRT-GAN: A defect-aware deep adversarial network to perform super-resolution tasks in infrared thermographic inspection

InfraRed Thermography (IRT) is a valuable diagnostic tool for detecting defects in fiber-reinforced polymers in a non-destructive manner through the measurement of surface temperature distribution. Yet, thermal cameras typically have a low native spatial resolution resulting in a blurry and low-quality thermal image sequence.This study proposes a defect-aware Generative Adversarial Network (GAN) framework, termed Dual-IRT-GAN, in order to simultaneously perform Super-Resolution (SR) and defect detection tasks in infrared thermography. Furthermore, the visibility of defective regions in generated high-resolution images are enhanced by leveraging defect-aware attention maps from segmented defect images.Following a series of augmentation techniques and a second-order degradation process, the proposed Dual-IRT-GAN model is trained on an extensive numerically generated thermographic dataset of composite materials with various defect types, sizes and depts. The high inference performance of the virtually trained Dual-IRT-GAN is demonstrated on several experimental thermographic datasets which were obtained from composite coupon specimens with various defect types, sizes, and depths, as well as from aircraft stiffened composite panels having real (production) defects.

A Temperature Imaging Method for Multi-Chip High Power LEDs Based on the Magnetic Nanoparticle Thermometer.

In this study, a temperature imaging method based on a magnetic nanoparticle thermometer is proposed and evaluated. We first constructed a new model for finding the single temperature of magnetic nanoparticles with core size distribution. Specifically, we employed an air-core coil as a magnetic probe, which measured the magnetization of magnetic nanoparticles (MNPs). We then constructed a relation between the output signal of an air-core coil in the direction of the geometric center axis and the magnetization of the MNPs in a 2-D imaging area based on the magnetic dipole theory. Once this was achieved, we established a temperature imaging model by utilizing Green function as the convolution kernel, which describes the distance relationship between MNPs and the geometric center axis of the air-cored coil. After this, we calculated the harmonic distribution by a deconvolution algorithm and determined the temperature of the MNPs at different positions based on the model of harmonic amplitude and temperature, resulting in the 2-D temperature distribution. The simulation proved that the model and method of 2-D temperature distribution measurement could theoretically be acceptable. In the experiment, the 2-D temperature distribution of multi-chip power LEDs was measured accurately by a homemade system, thus demonstrating the feasibility of the proposed method for temperature imaging. This method is expected to provide a new solution for measuring the internal temperature distribution of opaque objects under extreme conditions.

Nine Channel Data Logger to Measure Temperature Distribution on Dry Stelizer based on Andoid system

A temperature measurement in sterilization is needed to find out whether the temperature setting has been reached, because if the tool is operated continuously it will have an impact on the performance of the tool. Data logger is a tool used to record time and temperature by recording. The purpose of this research is to develop technological advances with remote or automated systems that can monitor changes in temperature rise and fall. This study uses 9 types of K-type thermocouple sensors as temperature gauges which are placed at 9 specified points. A thermocouple is connected to the MAX6675 module for conversion which initially detects temperature into digital form data. Data processing uses the Arduino Mega 2560 system and the Arduino programming software processor. HC-05 is used as a data transmission of measured results that have been read where the results are displayed on Android using the Blynk application, the data sent will be in the form of Excel. This tool uses a temperature comparison from the MEMMERT UN 55 incubator in the microbiology laboratory. The error value contained in the 100°C temperature adjustment is 2.6% at a temperature of 1, the smallest error at temperatures 7 and 8 is 0.2% due to the location of the sensor far from the heater. The error value at a temperature of 150°C is 1.7%, the smallest error at temperature 5 is 0.3%, 0.5%. The error value at a temperature of 200°C is 1.8%, the smallest error at temperature 0.5%. This research is expected to make it easier for users to simultaneously monitor temperature and simplify data processing to obtain an accuracy error value in the unit under test (UUT).

Temperature Distribution in Bio Stove using Saw Dust: An Integrated Project-based Learning

This paper aims at developing the potential of cellulose-based energy generation using pyrolysis, gasification, and combustion methods with biodegradable waste media. The cellulose-based material used in this study was sawdust. The sawdust was heated using a biomass stove, which was then analyzed in terms of heat conduction and propagation as well as temperature distribution. To ensure the effectiveness of sawdust as the main material in the biomass stove, sawdust particles were pressed and compacted under various pressure conditions. This experiment was integrated with the Project-Based Learning method through the following steps: (1) determination of projects testing, (2) project design, (3) project implementation schedules, (4) project completion and progress monitoring, (5) reports and presentations of project results, and (6) project evaluation. The results provide new findings that the denser sawdust particles correlate with the greater temperature and propagation rate. This can be obtained from the measured temperature distribution. Areas close to the heat source tend to have the same heat propagation. The density of the sawdust particle is the main key point for producing better pyrolysis and gasification process, in which it correlates with long combustion energy. Integrasi This finding opens a new concept and can be used as a reference for other researchers who develop research related to renewable energy from waste, especially when using a biomass stove. This study also gives ideas for the need for developing project-based learning using the burning of sawdust using biomass stove as a tool for the teaching and learning process.

Characterization of the temperature distribution of a polymer permanent magnet synchronous motor with a fiber Bragg grating (FBG)

This article reports a distributed thermal monitoring approach for permanent magnet synchronous motors (PMSMs). The detecting system is based on using an electrically non-conductive and electromagnetic interference-free fiber Bragg grating (FBG) temperature sensor embedded in the stator of PMSMs. FBG thermal sensors with different annealing temperature were fabricated and integrated with a motor stator, and their accuracy for temperature measurement was evaluated. According to the experimental results, the error within 200 °C is limited between −6 °C and 2 °C when the annealing temperature is 95 °C, and the error decreases to ±1 °C when the annealing temperature is 120 °C, indicating that performance of FBG thermal sensor is improved by increasing the annealing temperature. This article provides methodogical guidance for improving the accuracy of stator temperature distribution measurements based on the FBG thermal sensor.

A new ultrasonic method for synchronous measurement of internal temperature distributions and thickness in high-temperature structures

A new ultrasonic method for synchronous measurement of multiple parameters of heated materials is proposed in this paper. Based on the thermal-acoustic-solid coupling theory, the internal temperature distributions and thickness of solid structures are reconstructed synchronously by an alternate iterative multi-parameter identification method. Firstly, a numerical model of multi-parameter synchronous identification is obtained based on temperature dependence of the velocity of the ultrasonic wave propagating through the heated material. Then, an inverse analysis by the alternate iterative method for estimating equivalent thermal boundary conditions and thickness. In addition, experiments are carried out in order to validate the feasibility and reliability of the developed method, whose stability and accuracy are also analyzed through a comprehensive parameter analysis. The research results show that the structure thickness obtained by the alternate iteration method based on ultrasonic transit time accords with the physical reality and the internal transient temperature profiles determined ultrasonically agrees well with those obtained using thermocouples installed in the steel. It demonstrates that the method proposed in this work is an effective multi-parameter synchronous measurement means to determine the internal transient temperature distribution and thickness of high temperature structures with high accuracy by ultrasonic pulse echo measurements.

Effect of rare earth ion on fluorescent properties of Eu(TTA)3phen/PMMA temperature sensitive paint

The temperature sensitive paint (TSP) technology is widely used in the temperature distribution measurement of large area solid field, especially for the in-depth research in the mechanical behavior of complex flow gas around the aircraft, because of its advantages of non-contact, full-field measurement, easy manufacture and use. In this work, we synthesized the rare earth ion(Y3+, Er3+) doped Eu(TTA)3phen/PMMA temperature sensitive paint respectively based on the probe molecules of the rare earth ion (Y3+, Er3+) doped Eu(TTA)3phen and polymethyl methacrylate(PMMA). The structure of probe molecules and the fluorescent properties of TSP were also studied. The result show that the optimal ratio of Eu3+:Y3+ (or Er3+) is 0.5:0.5, rare earth ions are coordinated with ligands and the doping of Y3+ and Er3+ do not affect the structure of Eu(TTA)3phen. Y3+ and Er3+ have gain effect on the fluorescent emission of Eu(TTA)3phen/PMMA and the strongest fluorescent intensity (616 nm) is decreased with the increasing of temperature, which show that the Y3+ and Er3+ doped Eu (TTA)3phen/PMMA have temperature quenching properties in the temperature range of 20–80 °C. What’s more, the doping of Y3+ and Er3+ can improve the change rate of the fluorescent intensity and the temperature measurement sensitivity.

Temperature Distribution Measurement and Internal Flow Visualization in the Lubrication Film of Non-contacting Mechanical Seals

The surface textures of non-contacting mechanical seals form a few micrometers thick lubrication film that aids in achieving high performance of the seal. Improved texture design can control internal fluid flow, improving the sealing performance and lubrication characteristics. However, film thickness is sensitive to thermal deformation, making seals vulnerable to heat. Excessive temperature increases and deviations in temperature distribution can cause performance degradation or damage to seals. Previous studies have suggested that heat transfer impacting these thermal issues may be influenced by the internal flow, however, experimental studies examining flow fields have not been conducted yet. This study presents the design of experimental equipment, measurement of temperature distributions and observation of flow fields in lubrication films with three different textures—non-textured, Rayleigh step, and spiral groove. Furthermore, the results were compared with those of numerical analysis. Temperature was found to be higher at the downstream end of the flow. In particular, the Rayleigh step seal exhibited a nonuniform temperature distribution that alternated between low and high-temperature areas. This was caused by cooling related to radial grooves that had a pumping effect. In contrast, a uniform temperature distribution was confirmed in the case of the spiral groove seal, which was formed by mixing outer and inner side fluids. The results indicate that the temperature distribution in lubrication films can be controlled via flow field by the surface texture shape or depth to protect against thermal degradation and to achieve high reliability of non-contacting mechanical seals.Graphical

Temperature characteristic of a gain fiber core in distributed side-coupled cladding-pumped fiber amplifiers with different pump schemes

In this paper, we study the temperature characteristic of a gain fiber core in distributed side-coupled cladding-pumped (DSCCP) fiber amplifiers by optical frequency domain reflectometry (OFDR). To the best of our knowledge, this is the first temperature distribution measurement of a fiber core in DSCCP fiber lasers. The temperature distributions are also firstly measured among forward, backward, and bidirectional pump schemes. In addition, the bidirectional pump scheme has lower temperature distribution than unidirectional pump schemes. The experimental fiber core temperature is in according with the numerical simulation, which was once introduced for the temperature study of DSCCP fiber amplifiers. By experimental measurement and theoretical modeling, it is found that the maximum core temperature is several tens of centimeters away from the injected end of the DSCCP fiber, such that it will distribute the heat load along the longitudinal direction and reduce the maximum thermal load with better thermal management advantages than ordinary double cladding fiber (DCF).