Search Results (729)

This study investigates tubing collapse resistance during low-temperature dense-phase CO₂ injection in carbon capture, utilization, and storage (CCUS) wells. A coupled temperature–pressure–tubing mechanics–collapse model was developed. CO₂ density, specific enthalpy, isobaric heat capacity, and the Joule–Thomson coefficient were calculated using the Span–Wagner equation of state, while wellbore temperature and pressure profiles were obtained from mass, momentum, and energy conservation equations. Tubing axial stress and triaxial collapse resistance were evaluated considering self-weight, thermal effects, ballooning, and fluid friction. Comparison with multi-depth measurements from one injection well produced bottomhole temperature and pressure errors of 0.99% and 0.71%, respectively. Sensitivity analysis showed that each 5 °C decrease in injection temperature reduced collapse resistance by approximately 2% on average. Each 5 MPa increase in injection pressure reduced it by only approximately 0.3% because the resulting combined-stress change was small relative to the tubing yield strength and the thermal contribution remained nearly unchanged. Increasing injection rate shortened heat-exchange time, lowered fluid temperature, and increased tubing loads, but had a weaker influence than injection temperature. The model provides a basis for optimizing injection parameters and verifying tubing strength. Full article

Deep tight-reservoir fracability depends on temperature, fluid transport, in situ stress, fracture development, and injection energy, so no single response can provide a defensible ranking of fracturing conditions. This study develops a sparse second-order Choquet–Monte Carlo fracability framework. Additionally, the CRITIC method is used independently to quantify the information contrast of the five evaluation indicators. This was done using true triaxial sequential dual-well experiments conducted at 25–200 °C, horizontal stress differences of 3–9 MPa, and with either supercritical CO₂ (SC-CO₂) or water. CT scanning, U-Net segmentation, and three-dimensional reconstruction supplied fracture volume and fractal dimension; two-stage breakdown pressures and hydraulic injection work described initiation accessibility and energy demand. The CRITIC information weights were 0.261 for stress compatibility, 0.235 for injection-work demand, 0.182 for fluid mobility, 0.172 for specimen temperature, and 0.150 for pressure accessibility. The fitted second-order model identified positive temperature–fluid (0.122) and temperature–stress (0.071) non-additive coefficients, while the pressure–work coefficient was close to zero (−0.008). Sequential injection produced a consistent stage-dependent difference in breakdown pressure, with the second-stage value exceeding the first-stage value in every test. This observation is interpreted descriptively within the fixed sequential injection protocol. Condition No. 5 (SC-CO₂, 200 °C, 3 MPa) ranked first with a fracability index of 0.935 and a 95% Monte Carlo interval of 0.908–0.945. Leave-one-out cross-validation gave a Spearman coefficient of 0.830 and R² = 0.860. Within the tested domain, temperature was associated with improved fracability, particularly under the low stress-difference condition where enhanced SC-CO₂ mobility and thermal effects acted together. The framework therefore distinguishes coupled benefits, redundancies, and uncertainty that an additive score would conceal. Full article

Simulation studies of surplus electricity in sugarcane cogeneration almost universally assume stable nominal operation, and the sector literature qualitatively acknowledges that many surplus projects underperform; however, this discrepancy has not been systematically quantified against multiyear operational records. Using daily records from seven harvest seasons (2010–2016; 931 valid days) of a Cuban low-pressure sugar mill and the previously published simulation of its own thermal scheme (Termoazúcar STA 4.1), this study quantifies the discrepancy through the Energy Performance Gap (EPG) framework adapted from building science. The export shortfall relative to the simulated baseline ranged from 19.0% to 49.3% per harvest (38.1% aggregated over 2010–2015; 12,835 MWh unrealized) and reached 28.9% for the five-mill provincial aggregate. The gap does not arise from idle capacity—availability is 0.98–1.00, and industrial demand matches the simulated value—but from conversion, with a cane-weighted generation deficit of 5.46 kWh/t ($-12.7$%). Plant steam records proved to be accounting allocations based on fixed coefficients and cannot support correlation-based inference; what they document independently is a contiguous start-of-season regime with pressure-reducing valves in service (39 days of a single harvest), during which specific generation was 11.9 kWh/t lower at statistically identical milling rates (26.15 vs. 38.06 kWh/t; $p<0.001$). No interannual trend was detected (Mann–Kendall, $p=0.368$), although statistical power is limited, at $n=7$. A Monte Carlo characterization of the parametric uncertainty of the simulated baseline (boiler efficiency $\pm 3$%, turbine isentropic efficiency $\pm 5$%, and bagasse moisture $\pm 2$ percentage points) shows that the existence of the gap is robust—the probability of no gap is, at most, 1.1%, even under worst-case uniform perturbations—while widening the intensity-level discount interval to [0.57; 0.93]; a start-of-season depression in specific generation recurs in four of the six estimable harvests, of which the 2015 reducer regime is the most severe instance. As case-specific correction tools, operational discount factors of 0.71 (95% block-bootstrap CI [0.68; 0.75]) for export intensity and 0.62 for total seasonal energy are derived; the underlying procedure, rather than the numerical values, is proposed as transferable. Full article

A membrane brine concentrator (MBC) can reduce the concentrate volume entering thermal processes for zero liquid discharge (ZLD). Previous LSRRO-based studies have largely focused on high-salinity brines using modified or specifically selected low-salt-rejection membranes. This study examined the extent to which water recovery could be increased in wastewater reclamation using conventional nanofiltration (NF) modules in MBC processes. Two brackish water reverse osmosis (BWRO) modules and two NF modules were tested in 2000–40,000 mg/L NaCl. NE4040-90 provided the best balance between salt-concentrating performance and required pressure. An NF module model was developed using experimentally estimated water permeability, salt permeability, and mass-transfer coefficient. It reproduced permeate concentration and feed pressure with normalized root-mean-square errors of 5.73% and 1.20%, respectively. The developed NF module model was then iteratively coupled with the upstream BWRO simulation to evaluate an integrated two-stage BWRO and three-stage MBC process. Compared with conventional BWRO, the integrated system increased overall recovery from 81.0% to 95.9%, reduced concentrate flow from 32 to 7 m³/h, predicted a final concentrate concentration of 51,396 mg/L, and maintained permeate concentration at 34 mg/L while remaining below the 41.4 bar pressure limit. The reduced concentrate load lowered total specific energy consumption from 4.5 to 1.6 kWh/m³ of wastewater feed under the adopted ZLD assumptions. Conventional NF modules therefore provide a practical option for high-recovery wastewater reclamation toward ZLD. Full article

Advanced engineering applications increasingly demand high-performance polymers with exceptional mechanical and thermal properties; however, predicting their processing behavior remains challenging due to complex rheological responses and the lack of integrated experimental–simulation frameworks. This study introduces a novel integrated experimental–computational methodology that combines comprehensive rheological characterization, multi-model fitting, injection molding simulation, and multiphysics finite element analysis (FEA) to investigate the processing capabilities of Polyether Ether Ketone (PEEK) for aircraft bearing applications. Unlike conventional approaches that treat rheological analysis, processing simulation, and structural assessment separately, our framework establishes a coupled material–process–performance relationship through: (i) systematic thermal and mechanical characterization, establishing PEEK’s high melting temperature (343 °C), degradation temperature (575 °C), and tensile strength (95 MPa); (ii) comparative rheological model fitting, demonstrating that the Carreau–Yasuda model accurately predicts non-linear flow behavior with R² = 0.97, outperforming simpler Power Law and Cross models; (iii) CAD-based injection molding simulation, revealing homogeneous flow distribution and optimized pressure profiles; and (iv) thermo-mechanical FEA, coupling thermal expansion with structural stress analysis to evaluate bearing integrity under operational conditions. The key novelty lies in the seamless integration of experimental rheology with multiphysics simulation, validated through rigorous statistical analysis achieving low RMSE (0.6854 MPa for stress, 0.003220 mm for deformation) and high correlation coefficients (R² = 0.97). The results confirm a uniform flow distribution, stable structural performance, and reliable thermo-mechanical response, establishing PEEK’s suitability for high-performance aerospace components. This work contributes a comprehensive, scalable, and transferable framework that bridges experimental analysis and advanced simulation, enabling the predictive optimization of polymer processing parameters and significantly enhancing manufacturing reliability for industrial applications. The findings demonstrate the applicability of the experimental–computational analysis to the investigated PEEK bearing configuration under the specified processing and simulation conditions. Its specific contribution is the application of comparative rheological model fitting and experimentally characterized PEEK properties to the selected bearing geometry and processing conditions. Full article

This study presents a computational comparison of 24 lattice topologies over their geometrically feasible relative density ranges. Conjugate heat transfer simulations were performed in ANSYS Fluent 2024 R2 using 10 mm unit cells, inlet air at 300 K and 0.05 m/s, a constant base temperature of 312 K, and gravity acting in the negative z direction. The inlet Reynolds number was approximately 32.5. The prescribed temperature difference of 12 K gives a Grashof number of 1.68 × 10³ and a Richardson number of 1.59, indicating that buoyancy and the imposed flow are both relevant. The operating condition was therefore classified as low-speed mixed convection with perpendicular forced flow and buoyancy directions. The hydrodynamic model was benchmarked against published pressure gradient data for a body-centered cubic lattice. Thermal performance was compared using interfacial area, the magnitude of the ANSYS Fluent surface heat transfer coefficient, interfacial heat transfer rate, and interfacial thermal resistance. At 10% relative density, Auxetic gave the lowest resistance, 112.34 K/W, compared with 327.51 K/W for Cube. At 70%, FBCC reached 97.56 K/W, whereas Cube reached 1028.12 K/W. Increasing relative density improved or degraded thermal performance depending on topology. The database provides comparative guidance for lattice selection and subsequent multiscale design optimization of lightweight aerospace and electronic heatsinks. Full article

The front-end wide-temperature-range gas-mixing flow system of a high-altitude test chamber is a key component for simulating inlet conditions over a wide temperature range, and the temperature uniformity of the mixed gas as well as the positional stability of the downstream interface directly affect the accuracy of the test boundary conditions. To address the nonuniform temperature field, thermal deformation of the main pipeline, and local thermal stress concentration arising from the combined effects of large temperature differences, long-distance piping, and high-pressure operating conditions, this study establishes a multiphysics coupling analysis framework based on ANSYS Fluent 2021 R1, CAESAR II, and ANSYS Mechanical, and systematically investigates the temperature distribution in the mixing section, thermal boundary transfer, the global thermal response of the piping system, locally refined models, and the compensating effect of expansion joints. The fluid–thermal results show that the temperature distribution of the mixed gas in the right-side section of the pipeline varies among the representative operating conditions, under which the branch mass-flow allocation, total flow rate, inlet total pressure, and inlet total temperature change simultaneously. To enable quantitative comparison, a temperature nonuniformity coefficient γ (the standard deviation of cross-sectional temperature divided by mean temperature) is introduced. For each temperature combination, Cases 1 to 3 represent operating conditions dominated by the 40 °C branch, whereas Cases 4 and 5 represent conditions dominated by the −70 °C branch in the 40 °C/−70 °C group and by the 550 °C branch in the 40 °C/550 °C group. Under the selected 40 °C/−70 °C cases, the γ values at the downstream monitoring section decrease from 8.72% in Case 1 to 3.86% in Case 3, confirming progressively smoother temperature distributions, whereas γ increases from 6.31% in Case 4 to 9.87% in Case 5, indicating stronger thermal stratification. Under the selected 40 °C/550 °C cases, γ reaches its minimum of 2.87% in Case 2, while the comparison between Case 4 (γ = 9.54%) and Case 5 (γ = 5.78%) shows that the increase in flow-rate difference in the dominant branch is associated with improved temperature uniformity. Thermo-structural coupling analysis further indicates that the main pipeline is the key component governing the overall thermal deformation of the system, that axial thermal expansion dominates under high-temperature conditions, and that local high stresses are mainly concentrated at fixed supports and in adjacent regions with abrupt geometric constraint changes. Further analysis demonstrates that expansion joints modeled using equivalent stiffness can reduce the Z-direction displacement at key locations of the main pipeline by 10.94, 16.46, 9.58, and 10.50 mm under four typical operating conditions, respectively, while shifting the critical region from the main pipeline support area to the vicinity of the compensating components. These results can provide a reference for controlling interface thermal displacement, designing the main pipeline structure, and arranging expansion joints in front-end gas-mixing systems. Full article

Severe friction and extreme temperatures occur at the tool–chip interface during metal cutting. Conventional cutting fluids struggle to penetrate interface micro-capillaries at the contact interface under high contact pressure. This issue causes severe tool–chip adhesion and accelerates tool wear. This study aims to solve fluid delivery limitations by introducing micro-textures with a depth of 15 microns on the tool surfaces. It reveals the mechanism of micro-textures in accelerating fluid penetration and reducing interface friction. An analytical capillary penetration model was established for conventional and micro-textured tools. Thermal penetration tests (30–150 °C) and turning experiments on hardened steel were conducted to evaluate interfacial fluid transport behavior. Theoretical modeling shows that micro-textures facilitate direct vapor-phase filling into micro-capillaries. This mechanism bypasses liquid ingress and droplet evaporation stages. This reduces the fluid penetration time into the capillaries by almost an order of magnitude. Thermal tests show that textured surfaces maintain dynamic vapor–liquid equilibrium. At 150 °C, the vapor penetration area reaches 978.5 × 10⁻³ mm² on micro-textures, over four times that of smooth surfaces. Energy dispersive spectrometry (EDS) detected fluid-derived sodium (0.98 at.%) inside micro-textured capillaries. Meanwhile, workpiece material adhesion decreases from 6.04 at.% to 0.11 at.%. In turning tests of AISI 1045 hardened carbon steel, micro-textured tools reduced the main cutting force by up to 17% and the axial force by up to 22%. Cutting temperatures decreased by up to 10.0%. The average tool–chip friction coefficient dropped by 9.2% at a cutting speed of 240 m/min. This work provides insights into a vapor-phase lubrication mechanism and offers quantitative guidance for designing high-efficiency self-lubricating tools. Full article

Leaf-level vapor pressure deficit ($VP{D}_{\mathrm{leaf}}$) depends on the temperature of the leaf surface as well as the temperature and humidity of the surrounding air. Therefore, instruments that estimate $VP{D}_{\mathrm{leaf}}$ from a fixed leaf–air temperature offset may introduce condition-dependent errors. This paper presents the development, uncertainty analysis, and validation of a low-cost, single-housing, portable sensor platform that directly measures air temperature ($T_{\mathrm{air}}$), relative humidity ($RH$), and leaf surface temperature ($T_{\mathrm{leaf}}$) via an SHT35 and an MLX90614 infrared thermometer, and computes $VP{D}_{\mathrm{leaf}}$ on-board in real time using an ATmega328-based microcontroller. The platform was validated against a Testo 610 thermo-hygrometer and a FLIR E4 thermal camera on two lettuce (Lactuca sativa L.) cultivars grown at 20–26 °C and 40–70 %RH. Coefficients of determination were $R^2=0.9607$ for $T_{\mathrm{air}}$ and $R^2=0.9382$ for $RH$ ($n=1017$). Leaf temperature and the on-board $VP{D}_{\mathrm{leaf}}$ output itself were validated against reference readings taken during randomly timed site visits on three separate days ($n=250$ after excluding apparent misreads): $T_{\mathrm{leaf}}$ showed $R^2=0.8852$ against the FLIR E4, and the device-computed $VP{D}_{\mathrm{leaf}}$ showed $R^2=0.9100$ against a reference $VP{D}_{\mathrm{leaf}}$ computed from the same reference readings, with a mean bias of $+0.008$ kPa and an RMSE of $0.046$ kPa. A propagation-of-error analysis separately yielded a worst-case $VP{D}_{\mathrm{leaf}}$ uncertainty of $\pm 0.153$ kPa under representative conditions ($T_{\mathrm{air}}=25$ °C, $T_{\mathrm{leaf}}=24$ °C, $RH=65\%$), mainly driven by the $\pm 0.5$ °C infrared sensor tolerance; the empirically observed error was well within this conservative bound. With a cost of USD 83.28, this platform provides a practical and economically accessible tool for real-time monitoring and VPD-informed decision making in vertical farms and greenhouses. Full article

This study investigated a high-temperature heat pump for industrial steam production at 200 °C. Considering refrigerant thermal degradation at elevated temperatures, R1336mzz(Z) was selected because of its thermal stability. Two systems were analyzed: a flash tank (FT) cycle producing steam using a water valve and flash tank, and a steam generator (SG) cycle directly generating steam in the gas cooler. Unlike previous studies focusing primarily on cycle-level thermodynamic performance, this study systematically compares two steam production configurations for a 3 MW-class HTHP by considering heat pump–steam loop interactions and further evaluates their economic and environmental feasibility through LCC and LCCP analyses. Applying an internal heat exchanger reduced the operating pressure and increased the heat pump coefficient of performance (COP) by up to 13%, depending on the pressurized water temperature. In the FT cycle, lowering the valve outlet temperature from 180 °C to 150 °C increased the heat pump COP to a maximum of 3.06. However, the additional mechanical vapor recompression (MVR) power limited the overall system COP to 2.29–2.44. In the SG cycle, the system COP ranged from 1.94 to 2.54 according to the saturated water temperature at the gas cooler inlet, although operation at lower water temperatures approached the critical region, resulting in a narrower operating margin. LCC and LCCP analyses showed that replacing conventional boilers with heat pumps reduced operating costs by 26–59%, depending on regional energy prices, with payback periods of 2.27–8.76 years. Heat pump adoption also reduced life cycle climate impacts by 13–72%. These results demonstrate that high-temperature heat pumps can provide an economically and environmentally viable alternative for industrial steam production at 200 °C. Full article

Bearing-grade PEEK composites are intended to improve sliding performance, but filler addition does not necessarily reduce friction. This study compared the dry sliding tribological behaviour of neat PEEK and hybrid PEEK containing PTFE, graphite, and carbon fibre against 42CrMo4+QT steel. Ring-on-block tests were performed at nominal PV values of 0.3–3.2 MPa·m/s, contact pressures of 0.87–5.82 MPa, and sliding velocities of 0.26–0.55 m/s. Each material–condition combination was tested using three independent specimens. Coefficient of friction was calculated from simultaneously measured tangential and normal forces, and subsurface temperature was recorded continuously. Initial and post-test surfaces were examined using optical and extended depth-of-field microscopy. Group mean COF values ranged from 0.052 to 0.123. Hybrid PEEK exhibited a higher numerical mean COF than neat PEEK in all six operating conditions, with relative differences of approximately 1.53–8.36%. Two-factor ANOVA estimated an overall hybrid-minus-neat difference of +0.003388 COF units (95% CI 0.001279–0.005496; p = 0.0029), whereas none of the six condition-specific neat–hybrid comparisons was significant after Holm correction. Initial temperature, maximum temperature, and baseline-normalised temperature rise were reported for every specimen and treated descriptively. Both materials reached stable sliding states without seizure or uncontrolled thermal escalation. Post-test EDF observations showed a denser pattern of fine grooves on neat PEEK, whereas hybrid PEEK exhibited comparatively smoother intervening regions interrupted by fewer but locally deeper features. Mass changes remained close to the capability of the applied balance and did not permit quantitative wear-rate comparison. The results show that the investigated hybrid formulation did not provide a dry-friction reduction advantage over neat PEEK under the tested conditions. Full article

Accelerating aridity and desertification driven by global climate change pose growing threats to dryland forest plantations, making it essential to understand transpiration dynamics across developmental stages for both forest-hydrology theory and the sustainable management of protective shelterbelts. This study compared transpiration characteristics, stomatal conductance (g_s), and water-regulation strategies between a 41-year-old mature stand and a 13-year-old young stand of Mongolian pine (Pinus sylvestris L. var. mongolica Litv.) on the southern margin of Horqin Sandy Land during the 2024 growing season, using thermal-dissipation sap-flow measurements combined with meteorological monitoring and water-potential sampling. Mean individual-tree daily transpiration in the mature stand (2.36 mm·d⁻¹) was approximately 2.6 times that of the young stand (0.90 mm·d⁻¹), yet the young stand showed a disproportionately stronger sap-flow response to small rainfall events. Sap flow in both stands was jointly driven by vapor pressure deficit (VPD) and photosynthetically active radiation, with a near-synchronous lag of ±10 min and tight canopy-atmosphere coupling (decoupling coefficients: 0.177 and 0.256, respectively), indicating transpiration was predominantly governed by stomatal regulation. Stomatal conductance declined with rising VPD in both stands, with a steeper decline in the mature stand. Water-potential analysis revealed pronounced anisohydric behavior in the mature stand (σ = 2.643, R² = 0.765, p < 0.01), and near-strict anisohydric regulation in the young stand (σ = 0.919, R² = 0.105, p > 0.05), indicating high tree-level hydraulic variability and precluding a definitive classification along the iso/anisohydric continuum for this developmental stage. Both g_s and transpiration increased with tree size, contradicting the hydraulic limitation hypothesis. These findings elucidate distinct water-use strategies between the young and mature Mongolian pine stands in this paired design and provide a physiological basis for stage-differentiated, precision water management of dryland shelterbelt plantations. Full article

This study investigates the heat transfer and fluid flow characteristics of six triply periodic minimal surface (TPMS) structures, specifically Gyroid (G3P6, G3P7, G3P8, G1P7) and Diamond (D1P7 and D3P7) configurations, using both experimental and numerical methods. Comparative analysis was conducted to evaluate the impact of adding a base to these structures on their thermal and hydraulic performance. The TPMS structures were assessed in terms of measured surface temperature, convection heat transfer coefficient, Nusselt number, overall thermal resistance, pressure drop, friction factor, and overall thermal–hydraulic performance. Results indicate that base-free structures exhibit better heat dissipation, with surface temperatures increasing by 1.2 °C (G3P6) to 5.5 °C (D3P7) when the base is added. The addition of the base reduces the convection heat transfer coefficient on average by 3.9% (G3P6) to 23% (D1P7) and increases overall thermal resistance by 3.1% (G3P6) to 28.7% (D1P7). The friction factor also rises by 6.1% (D1P7) to 47.3% (G3P6) due to the addition of the base. When the base is added, the overall thermal–hydraulic performance declines by 8.5% (G3P7) to 33.6% (D3P7), with Diamond structures experiencing a more significant reduction compared to Gyroid structures. Among the Gyroid structures, G3P6 (lower cell size and 60% porosity) demonstrated the lowest surface temperature and the highest heat dissipation capacity, while G3P8 (80% porosity) exhibited the lowest thermal performance. The Gyroid structure with larger cell size (G1P7) achieved the highest overall thermal–hydraulic performance, effectively balancing heat dissipation and fluid resistance. In contrast, when the base is integrated, the Gyroid structure with a smaller cell size and lower porosity (G3P6) showed the lowest overall thermal–hydraulic performance. Full article

Thermal transpiration enables a Knudsen pump to transport gas without moving components. An axial-integration formulation based on pre-computed transport coefficients from the linearized Shakhov kinetic model is applied to a single-stage unit comprising a circular microchannel and a circular macrochannel in series, with opposite wall-temperature gradients. The pressure-generation and gas-transport capabilities are characterized by the maximum pressure difference or thermomolecular pressure difference (TPD), the maximum mass flow rate, the equivalent TPD, the equivalent flow resistance, and the complete mass-flow-rate–pressure-difference characteristics. The principal quantitative calculations cover temperature differences ranging from 10 to 50 K, while the 75 and 100 K cases are retained only to assess the persistence of the calculated trends. The formulation reproduces benchmark experimental TPD data with a maximum absolute relative deviation of 12.5% and a mean absolute relative deviation of 6.7%, and shows excellent agreement with numerical data from the literature, with deviation below 1%. A decomposition of the microchannel and macrochannel contributions shows that a macrochannel contributing little to the total equivalent flow resistance may nevertheless produce appreciable reverse thermal transpiration. At the baseline condition of the study and for an inlet pressure $P_i=10 \mathrm{kPa}$, the macrochannel contributes only 0.37% of the total equivalent flow resistance but cancels 15.2% of the microchannel equivalent TPD. Over $P_i=1\text{–}50 \mathrm{kPa}$, the temperature-difference sensitivity of the TPD ranges from 0.93 to 1.05, whereas the microchannel-radius sensitivity varies from −0.41 to −1.62. For the maximum mass flow rate, the microchannel-radius sensitivity ranges from 2.06 to 2.56 and the microchannel-length sensitivity remains close to −1, while the macrochannel-length effect is negligible. Increasing the macrochannel radius improves both limiting outputs, i.e., TPD and maximum mass flow rate, but with progressively diminishing benefits from further enlargement of the macrochannel. These results provide a quantitative basis for preliminary dimension selection while explicitly identifying the limitations associated with linearization, finite channel length, fully developed flow, and neglected interface losses. Full article

This work presents a numerical investigation of a direct oil cooling system for Axial Flux Permanent Magnet (AFPM) machines. Building upon the authors’ previous study, which established the fundamental fluid dynamic mechanisms governing oil jet impingement on curved coil surfaces, the present research extends the analysis by performing a systematic parametric optimization of nozzle diameter and axial position. A validated CFD model, benchmarked against experimental data from the literature, is employed to quantify the influence of jet momentum, stagnation pressure, and flow attachment on the resulting thermal performance. Nine configurations are simulated at constant coolant mass flow rate, revealing that the nozzle diameter is the dominant parameter: smaller diameters generate higher jet velocities, stronger stagnation regions, and larger jet-induced forces, leading to significantly enhanced heat transfer coefficients and Nusselt numbers. Nozzle height plays a secondary yet relevant role, as higher positions promote a more coherent jet core and improve impingement quality. Among the nine simulated cases, the configuration with D = 3 mm and L = 14 mm achieves the lowest hotspot temperature and the most efficient energetic behavior within the simulated set, with only a modest increase in pumping power. The results confirm that direct oil impingement is highly sensitive to jet momentum and angle of attack and demonstrate that optimized nozzle design can substantially improve the thermal management of high power density AFPM machines. This extended analysis provides quantitative references for nozzle sizing and placement within the simulated operating conditions with enhanced cooling efficiency. Full article