Symmetric Temperature Distribution Research Articles

Effects of horizontal self-rotation on flow and heat transfer of supercritical n-decane in regenerative circular/rectangular cooling channels

Concerning the rotation flight of a hypersonic vehicle centered on its geometric axis, the rotational flow and heat transfer characteristics of supercritical n-decane in horizontal circular and rectangular tubes were comprehensively analyzed based on numerical simulation. The computational domain was established and the corresponding governing equations of mass conservation, momentum conservation, and energy conservation were mathematically formulated as well were the thermophysical properties and boundary conditions. A procedure for setting up the numerical simulation was finally implemented. A mesh independence study in the case of a rotating speed of 300 rpm and a turbulence model study based on a stationary/swinging tube were comprehensively conducted and the RANS model was well validated. For the circular tube, the wall temperature distribution trend along the flow direction is similar but the magnitude is not uniform. Also, the fluid temperature near the upper wall is larger than that in the vicinity of the lower wall, i.e., the relaminarization plays an essential role in this phenomenon. The velocity difference near the wall can be weakened by the centrifugal force. For the rectangular tube, the velocity magnitude and temperature distribution are found to be greatly affected by the rotation (i.e., centrifugal force). The relative temperature magnitude near the upper and lower walls will be reversed at a rotation speed of n = 100–500 rpm. Subsequently, a symmetrical temperature distribution can be observed once the speed increases to a certain value (e.g., n = 700–900 rpm). In summary, the centrifugal force plays a more important role in a rectangular tube than in a circular tube.

Effects of frequency on the AC flash sintering behavior and microstructure of Ga-LLZO

In this paper, the effects of frequency on the flash sintering behavior and microstructure of Li6.4Ga0.2La3Zr2O12(0.2Ga-LLZO) were investigated. The results showed that an increase in frequency had little effect on the onset temperature, but this increase reduced the duration of the weak current stage the incubation stage. Moreover, this phenomenon led to a decrease in the power loss during the constant current stage. Scanning Electron Microscope images showed that the microstructure was symmetrically distributed, and the uniformity increased with increasing frequency. Finite element simulations and an IR thermocamera were used to analyze the temperatures of the specimens. The symmetric distribution of temperature during the flash sintering process was the root cause. The results of AC impedance spectroscopy showed that when the frequency of flash sintering was ≥ 400 Hz, the ionic conductivity of Ga-LLZO was greater than that of conventional sintering. The results of this work demonstrated the important role of frequency in controlling the microstructures of ceramic materials in flash sintering.

Application of Homotopy Analysis Transform Method for Solving a Fractional Singular One-Dimensional Thermo-Elasticity Coupled System

This article extends the application of fractional-order time derivatives to replace their integer-order counterparts within a system comprising two singular one-dimensional coupled partial differential equations. The resulting model proves invaluable in representing radially symmetric deformation and temperature distribution within a unit disk. The incorporation of fractional-order derivatives in mathematical models is shown to significantly enhance their capacity for characterizing real-life phenomena in comparison to their integer-order counterparts. To address the studied system numerically, we employ the q-homotopy analysis transform method (q-HATM). We evaluate the efficiency of this method in solving the problem through a series of illustrative examples. The convergence of the derived scheme is assessed visually, and we compare the performance of the q-HATM with that of the Laplace decomposition method (LDM). While both methods excel in resolving the majority of the presented examples, a notable divergence arises in the final example: the numerical solutions obtained using q-HATM converge, whereas those derived from LDM exhibit divergence. This discrepancy underscores the remarkable efficiency of the q-HATM in addressing this specific problem.

MHD Free Convection Flows for Maxwell Fluids over a Porous Plate via Novel Approach of Caputo Fractional Model

The ultimate goal of the article is the analysis of free convective flow of an MHD Maxwell fluid over a porous plate. The study focuses on understanding the dynamics of fluid flow over a moving plate in the presence of a magnetic field, where the magnetic lines of force can either be stationary or in motion along the plate. Further, we will investigate the heat and mass transfer characteristics of the system under specific conditions: constant species and thermal conductivity as functions of time. The study involves a symmetric temperature distribution that provides heat on both sides of the plane. Our analysis includes the study of the model for different instances of plate motion and variations in temperature. The fluid dynamics of the system are mathematically described using a system of fractional-order partial differential equations. To make the model independent of geometric units, dimensionless variables are introduced. Moreover, we employ the concept of fractional-order derivative operators in the sense of Caputo, which introduces a fractional dimension to the equations. Additionally, the integral Laplace transform and numerical algorithms are utilized to solve the problem. Finally, by using graphical analysis the contribution of physical parameters on the fluid dynamics is discussed and valuable findings are documented.

A Review of Advanced Cooling Strategies for Battery Thermal Management Systems in Electric Vehicles

Electric vehicles (EVs) offer a potential solution to face the global energy crisis and climate change issues in the transportation sector. Currently, lithium-ion (Li-ion) batteries have gained popularity as a source of energy in EVs, owing to several benefits including higher power density. To compete with internal combustion (IC) engine vehicles, the capacity of Li-ion batteries is continuously increasing to improve the efficiency and reliability of EVs. The performance characteristics and safe operations of Li-ion batteries depend on their operating temperature which demands the effective thermal management of Li-ion batteries. The commercially employed cooling strategies have several obstructions to enable the desired thermal management of high-power density batteries with allowable maximum temperature and symmetrical temperature distribution. The efforts are striving in the direction of searching for advanced cooling strategies which could eliminate the limitations of current cooling strategies and be employed in next-generation battery thermal management systems. The present review summarizes numerous research studies that explore advanced cooling strategies for battery thermal management in EVs. Research studies on phase change material cooling and direct liquid cooling for battery thermal management are comprehensively reviewed over the time period of 2018–2023. This review discusses the various experimental and numerical works executed to date on battery thermal management based on the aforementioned cooling strategies. Considering the practical feasibility and drawbacks of phase change material cooling, the focus of the present review is tilted toward the explanation of current research works on direct liquid cooling as an emerging battery thermal management technique. Direct liquid cooling has the potential to achieve the desired battery performance under normal as well as extreme operating conditions. However, extensive research still needs to be executed to commercialize direct liquid cooling as an advanced battery thermal management technique in EVs. The present review would be referred to as one that gives concrete direction in the search for a suitable advanced cooling strategy for battery thermal management in the next generation of EVs.

Individual Effect of Spatially Periodic Vertical Surface Temperatures and Nanoparticles on Natural Convection in Water

Abstract This paper considers the thermo-convective boundary-layer flow (BLF) of a water–copper mono-nanofluid over a flat vertical surface which is subjected to three types of periodic temperature variations described by the sinusoidal, sawtooth, and triangular waveforms. The temperature of the fluid at the flat surface is greater than the surrounding ambient temperature. The governing equations describing the BLF have been reduced to a non-similar form using an appropriate stream function formulation. The Keller-Box method is used to obtain numerical solution of the boundary-value problem. The effect of the pertinent parameters on the nature of the flow and the heat transfer has been discussed using actual thermophysical data. The results about the shear–stress and heat transfer rate at the surface are presented as well. To study the nature of BLF, the velocity and thermal boundary-layers, the streamline and isotherm plots have been considered, which reveal that the nanoparticle volume-fraction, amplitude of surface temperature variations, and the Grashof number play a pivotal role in enhancing/diminishing heat transfer. The final outcome reveals that the heat transfer is highest for the sinusoidal waveform, followed by that of the triangular and then, the sawtooth. An important inference is that a symmetric periodic temperature distribution at the surface enhances heat transfer more than that of a constant surface-temperature.

Numerical Simulation on Heat Transfer Augmentation by Using Innovative Hybrid Ribs in a Forward-Facing Contracting Channel

This study aims to investigate the thermal behavior and aerodynamic phenomena in a heated channel with varied rib configurations using computational fluid dynamics (CFD) simulations. Incorporating ribs in such systems enhances heat transfer and increases flow resistance and manufacturing costs. Understanding heat exchanger theory, measurement methods, and numerical calculations are crucial for creating efficient heat exchangers. The current research employs numerical analysis to assess the impact of hybrid ribs on heat transfer enhancement in forward-facing contracting channels (FFS). A two-dimensional forced convection heat transfer simulation under turbulent flow conditions was performed, considering the presence and absence of ribs with dimensions of 1 cm by 1 cm and spaced 11 cm apart. The arrangement of the ribs causes symmetrical temperature and flow distribution after and before each rib. The results demonstrate that the use of hybrid ribs outperforms the use of individual rib configurations in terms of thermal performance. This is due to the distinct flow patterns generated as the fluid passes through each rib. The triangle ribs had a more significant impact on the pressure drop than other rib configurations, while the cross ribs showed a lesser effect. The ribs improve the heat transfer coefficient while increasing the pressure drop, and the values of the Reynolds number were found to be directly proportional to the heat transfer coefficient and the pressure drop. The study concludes with a qualitative and quantitative analysis demonstrating the accuracy and coherence of the obtained computational results.

Efficient Cooling System for Lithium-Ion Battery Cells by Using Different Concentrations of Nanoparticles of SiO2-Water: A Numerical Investigation

The performance, safety, and cycle life of lithium-ion batteries (LiBs) are all known to be greatly influenced by temperature. In this work, an innovative cooling system is employed with a Reynolds number range of 15,000 to 30,000 to minimize the temperature of LiB cells. The continuity, momentum, and energy equations are solved using the Finite Volume Method (FVM). The computational fluid dynamics software ANSYS Fluent is applied to calculate the flow and temperature fields and to analyze the thermal management system for 52 LiB cells. The arrangement of batteries leads to symmetrical flow and temperature distribution occurring in the upper and lower halves of the battery pack. The impacts of SiO2 distributed in a base fluid (water) are investigated. The results show that SiO2 nanofluid with the highest volume fractions of 5% has the lowest average temperature values at all investigated Reynolds numbers. The innovative cooling system highlights the enhancement of the cooling process by increasing the SiO2 concentrations, leading to the recommendation of the concentration of 5 vol% due to better thermal diffusion resulting from the enhanced effective thermal conductivity. The flow turbulence is increased by increasing the Reynolds number, which significantly enhances the heat transfer process. It is shown that increasing the Re from 15,000 to 22,500 and 30,000 causes increases in the Nu value of roughly 32% and 65%, respectively.

Experimental study on the impact of asymmetric heavy rainfall on the smoke spread and stratification dynamics in tunnel fires

This work examines the impact of heavy rainfall on the smoke spread and stratification dynamics in tunnel fires with a reduced-scale (1:15) experimental platform. Scaled tests vary the rainfall intensity (up to 60 mm/h, equivalent to 232 mm/h in nature), raindrop size (1.0–1.5 mm, equivalent to 4–6 mm in nature), and fire heat release rate (2.1–6.7 kW, equivalent to 2–6 MW in real scale). We found that the asymmetric rainfall on one exit can induce the longitudinal airflow inside the tunnel due to the dissipation of the raindrop momentum and the rain-induced air entrainment. The velocity of such a longitudinal airflow increases with increasing rainfall intensity, and smaller raindrops tend to induce faster longitudinal airflow. The spread and stratification of hot smoke are sensitive to the induced airflow. In the absence of rainfall, there was a symmetrical temperature distribution from the fire source due to the symmetrical air entrainment. Under rainfall, the temperature distribution of tunnel fires gradually becomes less symmetrical, and the smoke stratification interface becomes unclear. With the increase in rainfall intensity, the phenomenon of smoke back-layering appears, and the smoke layer height decreases. Under a small rainfall intensity, raindrop size has a higher impact on the smoke stratification near the fire source. This study aims to attract more attention to tunnel safety under the dual disaster of fire and extreme weather and support the emergency response.

Numerical Study on Heat Transfer Characteristics of Dielectric Fluid Immersion Cooling with Fin Structures for Lithium-Ion Batteries

Electric vehicles (EVs) are incorporated with higher energy density batteries to improve the driving range and performance. The lithium-ion batteries with higher energy density generate a larger amount of heat which deteriorates their efficiency and operating life. The currently commercially employed cooling techniques are not able to achieve the effective thermal management of batteries with increasing energy density. Direct liquid cooling offers enhanced thermal management of battery packs at high discharging rates compared to all other cooling techniques. However, the flow distribution of coolant around the battery module needs to be maintained to achieve the superior performance of direct liquid cooling. The objective of the present work is to investigate the heat transfer characteristics of the lithium-ion battery pack with dielectric fluid immersion cooling for different fin structures. The base structure without fins, circular, rectangular and triangular fin structures are compared for heat transfer characteristics of maximum temperature, temperature difference, average temperature, Nusselt number, pressure drop and performance evaluation criteria (PEC). Furthermore, the heat transfer characteristics are evaluated for various fin dimensions of the best fin structure. The heat transfer characteristics of the battery pack with dielectric fluid immersion cooling according to considered fin structures and dimensions are simulated using ANSYS Fluent commercial code. The results reveal that the symmetrical temperature distribution and temperature uniformity of the battery pack are achieved in the case of all fin structures. The maximum temperature of the battery pack is lower by 2.41%, 2.57% and 4.45% for circular, rectangular, and triangular fin structures, respectively, compared to the base structure. The triangular fin structure shows higher values of Nusselt number and pressure drop with a maximum value of PEC compared to other fin structures. The triangular fin structure is the best fin structure with optimum heat transfer characteristics of the battery pack with dielectric fluid immersion cooling. The heat transfer characteristics of a battery pack with dielectric fluid immersion cooling are further improved for triangular fin structures with a base length -to -height ratio (A/B) of 4.304. The research outputs from the present work could be referred to as a database to commercialize the dielectric fluid immersion cooling for the efficient battery thermal management system at fast and higher charging/discharging rates.

Multchip SiC-based compact module for automotive applications: A high speed thermal study

Nowadays the increasing demand of high-efficiency power devices for automotive framework, forced the scientific community to develop new technologies capable to operate under intense power loads. Among the broad scenario SiC-based substrates represent a promising solution. This study focuses on a high-speed thermal characterization of a power module designed by STMicroelectronics (ACEPACK DRIVE) with the aim to provide a map of the temperature values reached at the surface upon current-pulse stresses. Thermal images collected on one leg show a symmetrical temperature distribution, with a maximum of around 60 °C on the device metals and ensures that any reliability issues due to the thermo-mechanical stress are avoided.

Measuring the Nonaxially Symmetric Surface Temperature Distribution of the Central Compact Object in Puppis A

Abstract The surface temperature distributions of central compact objects (CCOs) are powerful probes of their crustal magnetic field strengths and geometries. Here we model the surface temperature distribution of RX J0822−4300, the CCO in the Puppis A supernova remnant, using 471 ks of XMM-Newton data. We compute the energy-dependent pulse profiles in 16 energy bands, fully including the general relativistic effects of gravitational redshift and light bending, to accurately model the two heated surface regions of different temperatures and areas, in addition to constraining the viewing geometry. This results in precise measurements of the two temperatures: kT warm = ( 1 + z ) × 0.222 − 0.019 + 0.018 keV and kT hot = (1 + z) × 0.411 ± 0.011 keV. The two heated surface regions are likely located very close to the rotational poles, with the most probable position of the hotter component ≈ 6° from the rotational pole. For the first time, we are able to measure a deviation from a pure antipodal hot-spot geometry, with a longitudinal offset δ γ = 11 .° 7 − 2 .° 5 + 2 .° 6 . The discovery of this asymmetry, along with the factor of ≈2 temperature difference between the two emitting regions, may indicate that RX J0822−4300 was born with a strong, tangled crustal magnetic field.

Enhancement of Imperfection Detection Capabilities in TIG Welding of the Infrared Monitoring System

For a low cost, there are industrial infrared monitoring systems used for imperfection detection and identification in welded joints. The key drawback that impedes real life industrial applications is the low spatial resolution, as well as the temporal resolution of low-cost infrared (IR) cameras. This is also the case in tungsten inert gas (TIG) welding. Taking into consideration the influence of voltage on the arc energy and heat input, high frequency sampled voltage was used to evaluate the interpolated temporal resolution of IR sequences. Additionally, a reflected temperature correction method was proposed to reduce the uncertainty of absolute temperature measurement with a thermographic camera. The proposed method was applied to detect several imperfection types, such as lack of or incomplete penetration as well as incorrect weld shape and size (including burnouts). Results obtained for different interpolation factors were compared. The obtained results emphasize the validity of reflected temperature correction method. For the weld defects detection task, the smallest detectable defect was found for various interpolation factors. Moreover, the correspondence of arc voltage and the joint temperature was checked. Additionally, a set of decision rules was elaborated on and applied to distinguish between various joint conditions. It was found that defects that do not have symmetrical temperature distribution with respect to the joint axis are harder to identify.

Electric Field and Temperature Simulations of High-Voltage Direct Current Cables Considering the Soil Environment

For long distance electric power transport, high-voltage direct current (HVDC) cable systems are a commonly used solution. Space charges accumulate in the HVDC cable insulations due to the applied voltage and the nonlinear electric conductivity of the insulation material. The resulting electric field depends on the material parameters of the surrounding soil environment that may differ locally and have an influence on the temperature distribution in the cable and the environment. To use the radial symmetry of the cable geometry, typical electric field simulations neglect the influence of the surrounding soil, due to different dimensions of the cable and the environment and the resulting high computational effort. Here, the environment and its effect on the resulting electric field is considered and the assumption of a possible radial symmetric temperature within the insulation is analyzed. To reduce the computation time, weakly coupled simulations are performed to compute the temperature and the electric field inside the cable insulation, neglecting insulation losses. The results of a weakly coupled simulation are compared against those of a full transient simulation, considering the insulation losses for two common cable insulations with different maximum operation temperatures. Due to the buried depth of HV cables, an approximately radial symmetric temperature distribution within the insulation is obtained for a single cable and cable pairs when, considering a metallic sheath. Furthermore, the simulations show a temperature increase of the earth–air interface above the buried cable that needs to be considered when computing the cable conductor temperature, using the IEC standards.

Warm Hydroforming Process under Non-Uniform Temperature Field for Magnesium Alloy Tubes

The warm tube hydroforming (WTHF) process of lightweight materials such as magnesium alloy contributes to a remarkable weight reduction. The success of the WTHF process strongly depends on the loading path with internal pressure and axial feeding and other process variables including temperature distribution. Optimization of these process parameters in this special forming technique is a great issue to be resolved. In this study, the optimization of the symmetrical temperature distribution and process loading path for the warm T-shape forming of magnesium alloy AZ31B tube was carried out by finite element (FE) analysis using a fuzzy model. As a result, a satisfactory good agreement of the wall thickness distribution of the samples formed under the optimum loading path condition can be obtained between the FE analysis result and the experimental result. Based on the validity validation of FE analysis model, the optimization method was applied to other materials and forming shapes, and applicability was discussed.

Single and Double Drop Impingement on a Heated Plate CFD and Experimental Investigation

A drop impingement on a hot surface is known as an effective way for heat removal. The present work uses a VOF (volume of fluid) model to simulate the flow behavior and temperature distribution on a 50 °C heated plate while relatively cold water drop is impinging. The temperature distribution at the impingement zone is used to examine the transient heat transfer coefficients using a single drop and double drops conditions. The spreading factor is tested in both cases. A test rig is built to verify the temperature distribution and a heat balance method is introduced to find the experimental heat coefficients on the heated. The CFD solution and its flow results gives a good agreement for single drop previous results. The results for the double drop condition show a high tendency for rebound and splash of the drop leaving the central zone without water drop coverage which way causes a burn out in case of high heat fluxes. The single drop condition show a symmetrical temperature and heat transfer coefficients distribution while the double drop impingement gives lower value of coefficients with non-uniform and unsymmetrical distribution specially at the bigger drop to plate distances. The experimental average heat coefficients gives relatively low error of only 5% in case of double drop when compared to the single drop values.

Study on characteristics of particulate emission of diesel aftertreatment with reciprocating flow

AbstractIn this article, in order to optimize diesel aftertreatment system with periodically reciprocating flow (PRF), an experimental study is conducted to investigate its characteristics such as pollution emissions, regeneration of diesel particulate filter (DPF), concentration, and size distribution of particulate matter (PM) escaped as well as temperature distribution under unidirectional flow and PRF operating conditions. The effects of reciprocating flow cycle and exhaust gas flow on the performance of aftertreatment system are investigated in detail. The energy efficiency analysis of the aftertreatment system is also carried out. Experimental results show that (a) as the temperature is lower than the light‐off threshold of combustible gas, the aftertreatment system cannot restrain the formation of second particles under the low‐temperature condition of unidirectional flow; and (b) the aftertreatment system demonstrates excellent performance of trapping particles and filter regeneration as the symmetrical temperature distribution is formed. The PM filter efficiency is 92%, and the specific energy consumption β is 124% for symmetrical temperature distribution; (c) the increase in reciprocating flow cycle could lead to the shifting of the temperature profiles, and this would affect the particle size distribution; (d) a certain increase in exhaust gas flow from engine would have insignificant change for the temperature distribution; and (e) the critical energy efficiency of the system could reach 96.61%.

Study of Dust Properties of two Far Infrared Cavities near by Asymptotic Giant Branch stars under Infrared Astronomical Satellite Maps

The physical properties such as dust color temperature, dust mass, visual extinction, and Planck function with their distribution in the core region of two far-infrared cavities, namely FIC16-37 (size ~ 4.79 pc x 3.06 pc) located at R.A. (J2000): 16h 33m 57.25s & Dec. (J2000): -37d 47m 04.3s, and FIC12-58 (size ~ 22.54 pc x 14.84 pc) located at R.A. (J2000): 12h 52m 50.08s & Dec. (J2000): -58d 08m 55.02s, found within a galactic plane -10o to +10o nearby Asymptotic Giant Branch (AGB) stars namely AGB15-38 (R.A. (J2000): 15h 37m 40.74s & Dec. (J2000): -38d 20m 24.6s), and AGB12-57 (R.A (J2000): 12h 56m 38.50s & Dec. (J2000): -57d 54m 34.70s), respectively were studied using Infrared Astronomical Satellite (IRAS) survey. The dust color temperature was found to lie in the range of 23.95 ± 0.25 K to 23.44 ± 0.27 K with an offset about 0.5 K for FIC16-37, and 24.88 ± 0.27 K to 23.63 ± 0.98 K with an offset about 1 K for FIC12-58. The low offset in the dust color temperature indicated the symmetric distribution of density and temperature. The total mass of the cavities FIC16-37 and FIC12-58 were found to be 0.053 M☉ and 0.78 M☉, respectively. The contour plots of mass distribution of both of the cavities was found to follow the cosmological principle, suggesting the homogeneous and isotropic distribution of dust masses. The plot between temperature and visual extinction showed a negative correlation, suggesting that higher temperature has lower visual extinction and vice-versa. The distribution of Planck function along major and minor diameters of both of the cavities was found to be non-uniform, indicating oscillation of dust particles to get dynamical equilibrium. It further suggested the role of pressure-driven events nearby both cavities and suggested that dust particles are not in thermal equilibrium along the diameters.

The use of potential drop measurements to predict the temperature distribution in a thin wire with current flowing through it

When a current is supplied to a thin wire having smaller heat capacity, the temperature of the wire easily increases due to the principle of Joule heating. The temperature distribution in the wire has constituted an important issue for thin wire application. This paper reports a method to predict the temperature distribution in a thin wire through which current is flowing. The potential drops at the surfaces of thin Cu wires with diameters of 25 µm and 100 µm were measured. For these measurements the points of contact were close together, enabling us to measure the temperature dependency of the electrical resistivity of the wire. On the other hand, potential drop measured between the points of contact much further apart provided the information on the temperature distribution in the wire. By assuming the symmetric and parabolic temperature distribution, the temperature distributions in the Cu wires of 25 µm and 100 µm thick were predicted using the potential drop measurements made with the points of contact much further apart. The temperature distributions predicted were in good agreement with those measured by infrared thermography. The validity of the proposed method was also verified by conducting a similar experiment on Fe wire having a diameter of 100 µm.

Measurement of the in-plane temperature field on the build plate during polymer extrusion additive manufacturing using infrared thermometry

The process of filament-to-filament adhesion during polymer extrusion additive manufacturing (AM) is critically influenced by temperature distribution around the filament. Direct measurement of temperature distribution around the filament being deposited is, therefore, important for fully understanding this critical process. While past papers have reported side-view (x-z) temperature measurement using infrared (IR) thermography, this paper presents measurement of the in-plane (x-y) temperature field on the build plate during printing of the first layer by infrared thermography. This measurement is carried out from under the build plate. A small part of the build plate is replaced by an infrared-transparent window. In conjunction with an infrared right-angle prism mirror positioned underneath, direct measurement of in-plane temperature distribution is carried out with an infrared camera. With a thin graphite coating on the build plate, in-plane temperature field on the build plate is obtained, whereas experiments without the graphite coating result in direct measurement of the filament temperature distribution. Bottom-view measurements are shown to agree well with side-view measurements. Temperature fields on the build plate are measured as functions of time for single-line and multi-line printing. A few key features revealed by measurements include symmetrical and asymmetrical temperature distributions for single and multi-line printing, respectively, and the thermal influence between lines being limited only to the adjacent line. The in-plane temperature measurement approach complements past side-view measurements, and improves upon our understanding of thermal phenomena during polymer AM.