Surface Temperature Heat Research Articles

Effectiveness of light-oxygen therapy in plantar warts (clinical observation)

Purpose: to describe a clinical case of successful application of light-oxygen therapy (LOT) in a patient with plantar warts.Material and methods. The publication presents a clinical case of the successful outcome after light-oxygen therapy in the absorption spectrum of endogenous oxygen with its transfer to the singlet state in a patient with plantar warts. Russian-made diode laser «Super Seb», manufactured by LLC New Surgical Technologies (Moscow, Russia) with wavelength near 1265 nm, laser power 0–3 W was used as a source of laser light. Radiation power was from 2.1 to 2.7 W. Power density – from 0.86 to 1.86 W/cm2. Exposure dose – from 258 to 558 J/cm2. No anesthesia was required. The maximal surface heating temperature during the procedure was 41 °C. Temperature was controlled with non–contact infrared thermometer ELARI SmartCare model YC-E13 (manufactured by Zhengyang Yuncheng Medical Technology Co. Ltd., China) to eliminate thermal damage. Laser sessions were twice a week with 3–4 day intervals.Results. Complete clinical remission was achieved after 14 LOT sessions.Conclusions. Light-oxygen therapy is an effective and safe procedure for patients with plantar warts.

Simulation and Machine Learning Investigation on Thermoregulation Performance of Phase Change Walls

The outdoor thermal environment can be regarded as a significant factor influencing indoor thermal conditions. The application of phase change materials (PCMs) to the building envelope has the potential to improve the heat storage performance of building walls and, therefore, effectively regulate the temperature variations of the inner surfaces of walls. COMSOL Multiphysics software was adopted firstly to perform the simulations on the thermoregulation performance of phase change wall; the time duration of the temperature at the internal side maintained within the thermal comfort range was used as a quantitative evaluation index of the thermoregulation effects. It was revealed from the simulation results that the time durations of thermal comfort were extended to 5021 s and 4102 s, respectively, when the brick walls were filled with two types of composite PCMs, namely eutectic hydrate (EHS, Na2CO3·10H2O and Na2HPO4·12H2O with the ratio of 4∶6)/5 wt.% BN and EHS/5 wt.% BN/7.5 wt.% expanded graphite (EG), under the conditions of 18 °C ambient temperature and 60 °C heating temperature at the charging stage. Both of them were longer than 3011 s, which corresponds to a pure brick wall. EHS/5 wt.% BN/7.5 wt.% EG exhibited better leakage prevention performance and, therefore, was a candidate for actual application, in comparison with EHS/5 wt.% BN. Then, a machine learning training process focused on the temperature control effects of phase change wall was carried out using a BP neural network, where the heating surface and ambient temperature were used as input variables and the time duration of indoor thermal comfort was the output variable. Finally, the learning deviation between the raw data and the results obtained from machine learning was within 5%, indicating that machine learning can accurately predict the temperature control effects of the phase change wall. The results of the simulations and machine learning can provide information and guidance for the advantages and potentials of PCMs of hydrate salts when being applied to the building envelope. In addition, the accurate prediction of machine learning demonstrated its application prospects to the research of phase change walls.

Thermo-fluidic analysis of microchannel heat sink with inline/staggered square/elliptical fins

The present study reports the thermo-fluidic behavior of a microchannel heat sink employed over a heat source dissipating a heat flux of 50 W/cm2. The microchannel heat sink is embedded with elliptical and square fins varied from 11 × 3 (11 fins per row with a total of 3 rows) to 79 × 3 fins and 100 μm to 300 μm height to obtain the optimum configuration for maximum heat transfer and minimum frictional loss. Fluid flow is considered in the laminar range of Re varying from 100 to 400. The problem is solved numerically using a Finite Volume Method based multigrid solver of ANSYS Fluent. The aim of the present study is to investigate the shape effect of square fin (α = 0), square fin (α = 45) and elliptical fins on the heat transfer from the heater surface and frictional loss. This is achieved by keeping the correctional area and the surface the same for all types of fins. It is found that the heater surface temperature monotonously decreases with the number of fins for a fin height more than 200 μm. When different fin shapes are compared, no remarkable difference in the heater surface temperature is observed; however, elliptical fins are marginally more effective for a greater number of fins than the square fin with α = 0 followed by α = 45. Increasing the fin height results in augmenting the heat transfer for all cases. When different arrangements are compared, staggered fins result in slightly better heat transfer than the inline fins except 11 × 3 and 79 × 3 fins. As far as friction factor is concerned, elliptical fins with staggered arrangement provide the least frictional resistance.

Thermal-hydraulic performance of ammonia in manifold microchannel heat sink

With the increasing miniaturisation of electronic devices, the demand for cooling technologies with high efficiency has increased. Therefore, in this study, a manifold microchannel heat sink was designed and fabricated to enhance the dissipating capability of high-heat-flux hotspots. Owing to its excellent thermophysical properties, ammonia was selected as the working fluid, and its thermal–hydraulic characteristics were evaluated. In addition, the effects of flow rate, heat flux, saturation temperature, and inlet conditions were investigated through experiments. High-subcooled inlet experiments revealed that the thermal resistance decreased and pressure drop increased with increasing flow rate. Moreover, localised subcooled boiling was observed near the heated region. In near-saturated inlet experiments, jet impingement and microchannel cooling were identified as the dominant heat transfer mechanisms over different flow ranges. Notably, the higher heat flux, lower saturation temperature, and two-phase inlet condition reduced the thermal resistance under the operating conditions of the study. The proposed heat sink dissipated the heat flux (up to 1542 W/cm2) from the heat source (1 mm × 6 mm) with a pressure drop of 10.6 kPa, and the corresponding heating surface temperature and thermal resistance were 68.05 ℃ and 0.450 K/W, respectively.

CALCULATION OF GAS-DYNAMICS PARAMETERS AND STRESS-STRAIN STATE OF CELSIAN CERAMICS PRODUCTS

In the work using the finite element method, an analysis of the behavior of nose fairings made of radio-transparent ceramic materials of celsian composition was carried out. Determination of parameters of gas dynamics and stress-strain state was carried out using licensed ANSYS software. SSG Reynold Stress turbulence model was chosen for accurate air flow simulation. Geometric and finite element models were used to calculate strength and temperature fields. The analysis of the results of gas-dynamic calculations shows that at the point of transition of the conical part of the rocket into the cylindrical part, there is a sharp change in the flow conditions and a disruption of the flow in the range of speeds of 100-1100 m/s. As a result of modeling the distribution of temperature fields with the stated task, it was established that the temperature on the inner surface of the fairing differs from the temperature on the outer surface by no more than ±1 °C on average, and the maximum surface heating temperature does not exceed 550 °C. According to the results of calculations of the stress-strain state under temperature regimes that simulate the conditions of their operation, it was concluded that under the considered conditions the equivalent (≤ 69.3 MPa) and main (≤ 40 MPa) stresses occurring in the nose fairing are not exceed the bending strength limit for celsian ceramics (290 MPa). It can be observed that the maximum temperature difference in thickness corresponds to the part of the fairing with the minimum radius. Movements on the surface of the fairing do not exceed 0.25 mm, which is acceptable according to the specified parameters. The parametric model provides advantages in justifying rational technical solutions. Ultimately, the nose fairing, made of celsian ceramics, will maintain its integrity in real operating conditions. Keywords: radiotransparent celsian ceramics; nose fairing; finite element method; gas dynamics; thermophysical calculations; strength; stress-strain state

SiC Microchannel Heat Sinks for High Heat Flux Dissipation of 1 kW/cm2

Thermal management has become a major barrier in the development of high-power micro-devices. Microchannel heat sinks (MCHS) are a promising method to dissipate high heat fluxes from high power density devices. Reducing the thermal resistance will reduce the temperature increase of the electronic device, allowing for higher powers to be achieved while maintaining a safe operating temperature. This paper reports on the use of silicon carbide (SiC) microchannels to dissipate high heat fluxes up to 1 kW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> over a footprint of 0.25 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The use of high aspect ratio and decreased hydraulic diameter channels has allowed for very low thermal resistances to be achieved at higher heat duties compared to previous studies. The experiments performed resulted in heater temperatures of less than 60 °C and thermal resistances as low as 0.024 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> °C/W between the heater surface and fluid inlet temperature. The demonstrated thermal performance of the SiC MCHS is an encouraging means for dissipating heat from high power density microelectronic devices.

Phase change heat transfer in a vertical metal foam-phase change material thermal energy storage heat dissipator

A metallic foam heat dissipator for cooling electronic components was addressed. A heat dissipator is a partitioned aluminum container loaded along with aluminum metallic foam and saturated with paraffin wax. A heat flux at a surface contains a basic uniform flux and the step transient raise, which should be managed by a heat dissipator and a Phase Change Material (PCM). The regulating equations for a melting/solidification transfer of heat & momentum transport in a heat dissipator were instituted into a structure of partial differential equations. Then, the vital monitoring equations were converted into a general dimensionless type and solved by the Finite Element Method. A mesh adjustment technique & automated time-step control was employed to control the accuracy & convergence of the result automatically. An adaptation technique controls the mesh resolution at the melting/solidification interface. The dimensionless temperature of fusion is a vital factor in the control of the surface temperature and heat dissipator efficiency. Considering a fixed amount of material for walls, a heat dissipator with thick sidewalls and thin top and bottom walls results in slightly better thermal performance. Using a PCM heat sink could reduce the heated surface temperature by >175 % during the pulse load.

Laboratory evaluation of microwave heating and skid resistance of pavement friction surfacing using calcined bauxite and magnetite aggregates

A high friction surface treatment (HFST) with magnetite (MT) aggregates instead of conventional calcined bauxite (CB) aggregates as microwave absorbers were prepared in this paper. The deicing properties by microwave heating and long-term skid resistance of HFST with different proportions of CB and MT aggregate were evaluated. The deicing properties by microwave heating of HFST were determined by electromagnetic characteristics, heating surface temperature, and microwave deicing time (MDT) tests. The long-term skid resistance of the HFST was characterized by conducting dynamic friction coefficient and mean profile depth (MPD) tests after long-term polishing using a three-wheel polishing device. The results showed that the electromagnetic characteristics of HFST were enhanced greatly by the addition of MT. The microwave heating efficiency of HFST was enhanced by the increase of MT substitution rate, which further enhanced its microwave deicing efficiency. The microwave deicing efficiency of HFST with MT substitution rate of 25% was 1.4 times that of HFST with MT substitution rate of 0%. Long-term skid resistance of HFST was reduced by the addition of MT, however, HFST with MT substitution rate of 25% also maintained a terminal μ40 and μ60 above 0.7, which can provide higher friction comparable with other high friction aggregate such as taconite, basalt, emery and flint. To improve the deicing properties by microwave heating and maintain high skid resistance, 25% MT replacement rate in HFST is recommended.

GCN- and GRU-Based Intelligent Model for Temperature Prediction of Local Heating Surfaces

A boiler heating surface is composed of hundreds of tubes, whose temperatures may be different because of their positions, the influences of attempering water and flue gas. Using a criteria based on DBI, we propose to partition a heating surface into local ones, whose interactions in temperature are represented as a weighted Heating Surface Graph (HSG) at each point of time, and their current features are embedded in the HSG&#x0027;s nodes. Then, a local heating surface temperature prediction model WGCN-GRU is proposed. Graph Convolutional Network (GCNs) receive a series of HSGs, and extract the features of local heating surfaces and their spatial dependences in a time window. Features output by GCNs are finally directed to Gated Recurrent Units (GRUs) for temperature predictions. Experiments show that WGCN-GRU can averagely maintain the prediction error below 0.5&#x00B0;C. Compared with other models, it can reduce the errors by a rate from 5.6&#x0025; to 46.8&#x0025;, and shows advantages in RMSE and <inline-formula><tex-math notation="LaTeX">$R^{2}$</tex-math></inline-formula>. It also shows that the node-to-node weights for GCN can reduce the prediction error by 11.4&#x0025;.

Optimal parameter design of a slot jet impingement/microchannel heat sink base on multi-objective optimization algorithm

Jet impingement and microchannel cooling as effective cooling methods have been widely employed for thermal management of high heat flux electronics. In this work, a novel hybrid slot jet impingement/microchannel heat sink, combining the advantages of two cooling technologies, was proposed to achieve vertical flushing of the jet and timely discharge of the waste fluid. To further enhance the cooling performance, a 3-D numerical simulation was applied to evaluate the impact of inlet and outlet branch passage inclination ratios (Hin,1/Hin,2 and Hout,1/Hout,2), channel unit width (W1), channel width ratio (φ) and channel height (H3) on heat sink thermal-hydraulic characteristics. According to the parametric analysis, the variations in the inlet and outlet branch passage inclination ratios have significant effect on the mass flow distribution among the heat transfer channels. Afterward, to acquire the optimal compromise solution for practical applications, the artificial neural network training and multi-objective optimization algorithms, i.e. multi-objective particle swarm optimization (MOPSO) and multi-objective genetic algorithm (MOGA), are utilized to optimize the geometrical parameters, i.e. W1, φ and H3. During the optimization, the average heated surface temperature (T¯heat) and the total pressure drop (ΔP) are two conflicting objectives to evaluate the heat transfer and resistance characteristics. Finally, an optimal compromise solution (W1=1.03mm, φ=0.58 and H3=2.44mm) is chosen from the Pareto front by using the classical decision-making algorithm, i.e. TOPSIS. Compared with one objective minimization in the Pareto front, the optimal compromise solution has a sound balance between heat transfer and resistance performance. Additionally, for the optimal compromise solution, with an inlet velocity of 1.5 m/s and a heat flux of 200 W/cm2, the maximum and average temperature of the heated surface does not exceed 73 °C and 67 °C, respectively, and the total pressure drop is only 5.7 kPa.

Studying the effect of geometry of micro-cavity on pool boiling by LBM

Pool boiling heat transfer from structured surface is simulated numerically with a 3D OTRT (optimal two relaxation time) Lattice Boltzmann method. This work shows in detail that multiple bubbles grow and coalesce over hydrophilic (θ = 50°) surfaces in 3D view, heat flux transfers from heater surface to fluid, and temperature of heater surface varies with time. Specifically, four types of geometry in microstructure surfaces are examined and compared. It is found that heat flux of S5 is the highest and its wall temperature is the lowest. When compared with S0, the heat flux of S5~S7 increased a lot due to the easier formation of vapor blanket, and cubic shaped cavity alleviates largely this deterioration. Next, the large quantity of heat from the three phase contact line in the vicinity of side wall accounts for bubble nucleation and energy from the evaporation of thin liquid between bubbles and superheated wall helps bubbles to grow further. Besides, it is found that S5 increases nucleate site density, reduces boiling incipience superheat, and enhances remarkably heat transfer performance.

A polyethersulfone film porous wick for loop heat pipes

Loop heat pipe (LHP), which is the star-rated way to solve high heat flux heat transfer, is a promising heat dissipation technology for electronic devices. The optimized design of porous wick in LHP has become the key to increasing the heat transfer capacity and reducing costs. In this study, a polymer material-polyethersulfone (PES) film was chosen as the porous wick. Theoretically, the PES wick has a special structure with dual pore size, which achieves a synergistic enhancement of capillary force and permeability. The experimental investigation compared the heat transfer capacity of LHP with the PES wick, copper mesh wick, and sintered nickel powder wick. The PES wick shows a most significant performance than the other two wicks. The heating surface temperature remains 62 °C in a 55% filling ratio when the LHP is under 300 W heat load. The LHP system and evaporator have respectively the thermal resistance of 0.161 °C/W and 0.056 °C/W. In addition, PES wick shows great potential for application in the LHP field with the advantages of light weight, simple preparation, and low cost. This paper sheds some light on the LHP wick choice to enhance heat transfer.

Assessment of the two-phase thermosyphon loop with high filling ratio under anti-gravity

In various fields of thermal management and protection, such as vehicles, aircraft, and mobile electronic devices, it is crucial to transfer heat effectively from the top to the bottom. The use of a simple structure for this transfer can reduce the weight of the heat transfer system. Theoretical studies have demonstrated that the two-phase thermosyphon loop (TPTL) with a high filling ratio has the potential for excellent performance in anti-gravity applications. In this study, we investigate the thermal performance of a high filling ratio TPTL under anti-gravity conditions. Our results reveal that, contrary to previous understanding, a TPTL with a high filling ratio can effectively transfer heat in anti-gravity. However, we also found that the loop thermal resistance of TPTL under anti-gravity is greater than under gravity, and the heating surface temperature is higher. Additionally, we experimentally study the effect of inclination angles on anti-gravity performance, and our results indicate that smaller angles result in better heat transfer. Finally, we investigate the impact of cooling water temperature on thermal performance. Overall, considering the energy efficiency of the heat dissipation system and the heat transfer capacity of the device, it is not recommended to use cooling water at a lower temperature. This research sheds light on the potential for TPTLs to operate in anti-gravity conditions and supports their practical applications.

An additively manufactured manifold-microchannel heat sink for high-heat flux cooling

Active liquid cooling technique with great efficiency not only reduces power consumption but also effectively dissipates high heat flux. In this study, a manifold-microchannel heat sink (MMCHS) was monolithically fabricated by additive manufacturing, and the thermal and hydraulic performance was investigated in a closed loop. Utilizing AlSi10Mg powder, the laser powder bed fusion process was used to fabricate the complex heat sink structure by directly putting a 3D liquid routing manifold structure on a typical microchannel. The MMCHS, with an overall size of 30 × 15 × 9 mm3, can support a heated area of 10 × 10 mm2 and features a tapered structure to facilitate uniform coolant flow. This system contains microchannels with a width and height of 0.2 mm and 2 mm, respectively, with an aspect ratio of AR = 21. Our results show that the MMCHS can dissipate effective heat flux up to 240 W/cm2 with a mass flow rate of 395 g/min with a considerably low-pressure drop of 1.7 kPa and low heated surface temperature of 100 °C. The corresponding total thermal resistance is as low as 0.21 K/W. In addition, numerical simulations showed detailed flow information as well as good agreement with experimental data. Finally, methods for structural improvement of the manifold microchannel were suggested based on the experimental and numerical results.

On the use of natural and forced convection correlations in predictive CFD simulations of liquid pool fires

This paper presents a detailed analysis of predictive numerical simulations of liquid pool fires, i.e., a 1 m – diameter methanol pool, a 0.7 m × 0.8 m ethanol pool, and a 0.18 m – diameter heptane pool. The burning rate is predicted using the ‘film’ model, including empirical correlations for heat and mass transfer. Although the forced convection approach (used in Fire Dynamics Simulator, FDS 6.7.5) yields relatively good results in fuel evaporation rate, it is somewhat questionable from a fundamental standpoint for quiescent burning conditions. Therefore, the natural convection approach is implemented in FDS 6.7.5. The predicted burning rates are similar to the forced convection approach, but the fuel surface temperature is closer to the boiling point by the natural convection approach. Based on the extensive analysis for the methanol pool fire, a modified natural convection correlation is proposed. The latter is tested for the ethanol test with satisfactory results for the peak Heat Release Rate (HRR), burning time, and surface temperature (closer to the boiling point). The modified natural convection approach is further tested for the heptane pool fire. Improved predictions are obtained for the peak burning rate, the transient stage, and the surface temperature.

Thermal analysis on the evaporation of fluid covered by porous media subjected to ultrasound and air jet impingement

The porous layer subjected to air jet is set above fluid passing through heating surface to control its thickness and avoid drying up, as well as ultrasound is introduced at upstream to enhance convection in flowing channel, in which heat flux can be dispersed in convection between fluid and heating surface as well as evaporation on the outside surface of porous cover to the outside. Local thermal equilibrium (LTE) occurs in porous cover, and the effect of sound pressure from ultrasound on liquid fluid is introduced according to acoustic theory. Brinkman–Forchheimer extended Darcy equations and k-ε turbulent model together with the above formulas are employed to describe the heat transfer in fluid covered by porous media subjected to ultrasound and air jet impingement. The effects of ultrasound power and frequency, fluid layer thickness as well as porosity and particle size in porous cover on heat transfer are investigated. The performance evaluation criteria (PEC) is defined to evaluate thermal characteristics in the cases with ultrasound than those without. The 35.7% rise ratio of heat transfer coefficient in the mode with ultrasound power of 50 W happens than that without. The higher ultrasound power and lower frequency of ultrasound cause lower heating surface temperature and larger heat transfer coefficient. The simulations agree with available published experiment data. All results of this study can be considered into utilization of ultrasound and porous layer to enhance heat transfer in flowing channel.

Optimization of elliptical pin-fin microchannel heat sink based on artificial neural network

Conjugate fluid-solid heat transfer in a pin-fin microchannel heat sink is an effective way to dissipate heat from the heating surface with high heat flux. The introduction of fins increases the heat exchange area and enhances flow turbulence, while it increases the flow resistance at the mean time. The thermal-hydraulic performance of heat sink is affected by fin shape, density and flow parameters. In this paper, contrived numerical simulations of the flow and heat transfer process in elliptical pin-fin microchannel heat sink are carried out, including 2033 cases with different fin sizes, numbers and flow velocities. The simulation results show that the flow velocity and fin transverse width are the main factors affecting heat transfer and fluid flow. Three artificial neural networks are established to predict the average temperature, the temperature non-uniformity of heating surface and the pressure drop of microchannel. The predicted results show that the pump power and heating surface temperature are contradictory objectives. A microchannel with the optimal thermal-hydraulic performance is selected. It has numerous fins which are longer in the flow direction. The empirical correlations for Nusselt number and friction coefficient of the optimal microchannel are proposed.

Mixed convection heat transfer and transient flow of high-pressure gas in a large-scale cavity with rotating blade

Mixed convection heat transfer phenomenon, incorporating natural and forced convection process, occurs widely in natural and industrial fields. Nevertheless, few works have investigated numerically the turbulent mixed convection heat transfer within the large-scale structure under high-pressure condition. In this study, a three-dimensional numerical model of a large-scale closed cavity with two rotating blades and reactor has been built on account of the finite volume method, aiming to explore the mixed convection heat transfer and turbulent flow of internal high-pressure gas. Compressible gas with varying thermophysical properties was chosen as the heat transfer medium and the numerical model was solved by Unsteady Reynolds-Averaged Navier-Stokes (URANS). Turbulent flow and heat transfer, inside the enclosure and reactor, were compared through the variation of the Reynolds number (Re), gas pressure (P) and heating surface temperature (Th). The results signify that for given P and Th, varying Re has a consistent impact on the transient flow and heat transfer process inside the enclosure and reactor. The turbulent flow and thermal transport are enhanced as increasing the Re. When the Re = 900,000, an enhanced forced convection effect is found inside the reactor. Dissimilar impacts on the flow field and thermal transport inside the enclosure and reactor are found with changing gas pressure owing to the interaction of natural and forced convection. The flow field attenuates gradually as the increment in P, and thereby larger high-temperature zone is achieved at a smaller pressure inside the enclosure, whilst inside the reactor, faster heat conduction is attained at a bigger pressure. Changing heating surface temperature has a more significant influence on the flow field and heat transfer inside the reactor compared to the enclosure. Additionally, increasing the Re and Th has a smaller effect on the average Nusselt number (Nuavg) while a positive correlation between the Nuavg and P is obtained.

Numerical simulation on pore-scale pool boiling mechanisms of horizontal gradient porous metals

Horizontal gradient porous metals are proposed to solve the problem of nonuniform temperature distribution on the heating surface. The model of horizontal gradient porous metal is established based on the thermal response of metal skeletons. Pool boiling heat transfer performances of horizontal gradient porous metals are studied by phase-change lattice Boltzmann model. Horizontal porous metal layer thickness, wettability and thermal conductivity gradient effects on bubble behavior and heating surface temperature distribution uniformity are statistically analyzed. The results show that porous metals with horizontal thickness gradient can realize liquid-vapor channel separation, reduce the resistance of bubble rising, and improve the fresh liquid supplement. Compared with the uniform porous metal, the horizontal gradient porous metal with lateral hydrophobic surface or higher thermal conductivity has better boiling heat transfer performance and promotes heating surface uniform temperature distribution at low heat fluxes. The results provide a novel solution to improve the chip wall temperature uniformity for the stable operation of electronic equipment.

Spray and dynamic heat transfer induced by 2-methylfuran transient spray impingement on piston surface

In the face of increasing air pollution and stricter emission requirements, it is very important to reduce particulate matter emissions in engine exhaust. The presence of the attached liquid film in gasoline direct injection engines produced by spray impingement is an important reason for the increase in engine particulate emissions. The dynamic heat transfer induced by the spray impingement is a key factor affecting the evaporation and existence time of liquid film. In this paper, a single-hole injector was used to carry out 2-methylfuran (MF) spray impingement experiments. The macroscopic morphological characteristics and the dynamic heat transfer of transient spray impingement under different conditions were systematically studied. Spray particle size distribution and spray impact force were also measured to assist in explaining the underlying mechanism responsible for the dynamic heat transfer. The results show that the surface heat flux increases with the rise of initial piston surface temperature. Increasing the injection pressure makes the droplets have a stronger impact force and smaller average diameter, which enhances the heat flux and also produces more bounce and splash of droplets on piston surface. Both the number of small-size droplets and impact force are reduced by the intense evaporation caused by increasing the injection temperature, resulting in the decrease of heat flux and surface temperature reduction. Increasing the distance decreases the droplet diameter and impacting force, as a result, the heat transfer intensity is weakened.