Traditional swirl vane demisters are widely used in industrial wet flue gas desulfurization (WFGD) systems. However, they suffer from high operational pressure drop, severe wall erosion, and a sharp decline in demisting efficiency at high gas velocities due to the breakup and re-entrainment of wall liquid film under strong gas shear, making it difficult to meet increasingly stringent ultra-low emission requirements. To address these problems, this paper designs a novel guide vane demister with the comprehensive optimization objectives of high efficiency, low resistance, and erosion resistance. Based on the Eulerian-Lagrangian multiphase flow framework, a gas-liquid two-phase flow numerical model is established. The SST k-ω turbulence model is adopted to describe the turbulent gas flow, the Discrete Phase Model (DPM) is used to track droplet trajectories, and the Discrete Random Walk Model (DRWM) is coupled to account for the effect of turbulent fluctuations on droplet dispersion behavior. The droplet motion equation incorporates the coupled effects of drag force, centrifugal force, and gravity. Using the experimental data of a swirl vane demister from the literature as a benchmark, the pressure drop and demisting efficiency under different inlet gas velocities (1.76–3.49 m/s) are compared to validate the accuracy of the numerical model. On this basis, the structural design of the arc-shaped guide vane demister is completed, with key geometric parameters including a cylinder diameter D0=284 mm, a central column diameter Di=142 mm, a vane outlet angle α=45°, and five guide vanes. Three-dimensional numerical simulations are then performed, and a systematic performance comparison with the traditional swirl vane demister is conducted from multiple dimensions, including velocity field, pressure field, turbulent kinetic energy, and droplet concentration distribution.The model validation results show good agreement between the simulated pressure drop, demisting efficiency and the experimental values, with relative errors within 5%, confirming the reliability of the numerical model. Flow field analysis reveals that a stable "Rankine vortex" structure is formed inside the guide vane demister, with the tangential velocity exhibiting a typical "low at the center, high near the wall" distribution. Compared with the traditional swirl vane demister: (1) the peak tangential velocity decreases from approximately 7.5 m/s to approximately 4 m/s, a reduction of about 40%, and the velocity distribution is more uniform with more gradual axial decay, significantly reducing the impact energy of droplets on the wall and the risk of erosion; (2) the operational pressure drop is reduced by 30%–40% across the entire simulated gas velocity range, with substantially decreased flow resistance; (3) the demisting efficiency is consistently higher than that of the traditional swirl vane demister, reaching 100% when the inlet gas velocity exceeds 2.78 m/s, achieving complete droplet removal.Owing to its streamlined geometry, the guide vane demister effectively eliminates the large vortex dead zone on the leeward side of the vanes and reduces local flow resistance, providing a sustained and stable centrifugal force field. While maintaining high-efficiency gas-liquid separation, it significantly reduces operational energy consumption and wall erosion risk, successfully achieving the comprehensive performance optimization characterized by "high demisting efficiency, low operational energy consumption, and low wall erosion risk." The findings of this study reveal the flow field evolution and droplet separation mechanisms of the guide vane demister, providing a reliable theoretical basis for the innovative design and engineering application of demisters for industrial flue gas purification.

PURPOSE:This study aimed to summarize 8-year clinical outcomes for patients who underwent transcatheter aortic valve replacement (TAVR) with the J-Valve system and evaluate the long-term durability and hemodynamic performance of the valve. METHODS:Between July 2014 and June 2015, 21 patients underwent transapical TAVR with the J-Valve system. Systematic clinical and echocardiographic follow-up was conducted on 18 patients for up to 8 years. RESULTS:Eight years post-TAVR with the J-Valve system, the all-cause mortality rate was 16.7%, with no prosthesis failures or thrombosis. Moderate to severe valve deterioration was observed in 50% of patients with aortic stenosis (AS), whereas no such deterioration was noted in patients with pure aortic regurgitation (PAR). At 8 years following TAVR, the effective orifice area measured 2.27 ± 0.50 cm2 in patients with PAR and 1.35 ± 0.38 cm2 in those with AS. Additionally, patients with AS exhibited a mean pressure gradient of 17.90 ± 10.61 mmHg. Over 8 years, PAR patients experienced a significant reduction in left ventricular end-diastolic diameter from 61.50 ± 2.08 mm to 48.67 ± 7.23 mm (p < 0.001), whereas AS patients showed no significant change. CONCLUSION:The J-Valve system demonstrates favorable long-term outcomes in TAVR, with excellent durability and hemodynamic performance in PAR patients.

This article introduces a high-performance swirl-film conjugate cooling scheme with the novel ridged wall for the leading edge of a gas turbine blade and presents a numerical study of the aerothermal characteristics of the conjugate cooling using a conjugate heat transfer analysis. Aiming at further improving the cooling efficiency of the turbine blade leading edge, a novel scheme of enhanced swirl-film conjugate cooling with an internal ridged wall is proposed. The complex flow and heat transfer interactions on the blade leading edge cooling effectiveness are studied, including the external main flow, film injection jets, solid wall heat conduction, and internal coolant jets impingement on the curved wall. Detailed aerothermal characteristics of the swirl-film conjugate cooling are presented and compared with each other by analyzing the leading edge external and internal flow structures, heat transfer, and pressure loss under three different jet-wall configurations and for various blowing ratios. The numerical results are effectively validated by the steady-state infrared thermography experimental data. The results indicate that within the range of parameters studied, compared to the baseline leading edge jet impingement-film cooling, swirl-film cooling has increased internal heat transfer rates with more uniform distributions and an even lower internal pressure loss penalty. The averaged Nusselt numbers of the swirl-film cooling with a smooth curved wall can be increased by more than 30.2%, and the overall cooling effectiveness of the leading edge can be increased by 4.8-5.7%. In addition, the pressure loss is reduced by 9.3-10.3%. Furthermore, the proposed ridged wall enhanced swirl-film cooling exhibits superior cooling performance. Specifically, it increases the average Nusselt numbers of internal swirl cooling by over 54%, enhances the overall cooling effectiveness of the leading edge by 8.0-10.1%, and reduces pressure loss by 8.1-9.9%.

Abstract The substation inspection robot has low accuracy in positioning and indication reading of the pointer instrument. An algorithm design for indicator recognition is proposed. The algorithm mainly includes dial area extraction, scale line extraction and dial center determination, zero scale line determination, and indicator recognition. An experimental system for pointer instrument positioning and indication recognition is constructed to verify the proposed algorithm. The results indicate that the positioning accuracy of the two instruments is 90.5% and 100% respectively. Ten positioned instruments are selected, and the reading recognition error is 0.126. It shows that the proposed pointer instrument positioning and indication recognition algorithm can improve the efficiency of substation instrument recognition.

The paper presents a numerical study of the heat transfer, pressure loss, and flow characteristics of swirl cooling in elliptical tubes, which are compared to the counterpart of swirl cooling in a circular tube with a diameter of D = 50.0 mm under equal passage Reynolds numbers and equal jet Reynolds numbers. The swirl tubes with two kinds of fixed tube length of 12D and 20D are compared, where there are sequentially arranged three tangential jet inlets over the leading tube length of 12D. The numerical results show that the swirl tubes with the tube length of 12D has a much better heat transfer performance. Under equal passage Reynolds numbers, the elliptical swirl tubes with the tube length of 12D show appreciably higher Nusselt numbers by up to 22.8% and lower pressure loss coefficients by up to 69.0% than the circular tube. Under equal jet Reynolds numbers, the elliptical tubes can reduce the global heat transfer performance modestly by up to 25.6%, but reduce the pressure loss much significantly by up to 70.6%. Mostly due to much less pressure loss, the elliptical tubes have remarkably higher thermal performance in terms of the obtained heat transfer coefficient per unit pumping power for both L1 = 12D and L2 = 20D. The numerical simulations indicate that the suppression of elliptical tubes on the swirling flow development reduces the heat transfer on the wall between the jet inlets, and decreases the wall shear force and the pressure loss in the tube.

The effectiveness of latent heat energy storage units is redistricted by the low thermal performance and suboptimal layout of phase change materials (PCMs). This work not only innovatively proposes a method of synergetic enhancement through the combination of T-shaped fins and partitioned subzones but also further boosts performance by optimizing the structure of T-shaped fins and the layout of PCM partitions. The findings indicated that the fin structure and PCM layout exerted a profound influence on the melting performance. Compared with the non-partitioned cavity without fins, T-shaped fins could reduce the melting time by up to 68.5% and amplify the average integral heat transfer rate by up to 257.4%. Compared to non-partitioned rectangular fins, Tshaped fins could reduce the melting time by up to 37.4% and enhance the average integral heat transfer rate by up to 39.2%. Under the same fin structure, the partition method with decreasing PCM melting points from top to bottom was most conducive to enhancing melting performance. Compared to non-zoned cases, this subzone approach achieved a substantial decrease in melting time by up to 30.5% and a notable enhancement in the average integral heat transfer rate by up to 22.4%.

OBJECTIVE:Our study aimed to evaluate short- and long-term outcomes of patients who required emergent conversion from transcatheter aortic valve implantation (TAVI) to open surgery. Besides, the reasons and procedural settings of emergent cardiac surgery (ECS) were also reported. METHODS:We retrospectively reviewed the patients who underwent TAVI in our institution between 2012 and 2019 and collected the clinical data of cases who converted from TAVI to bail-out surgery. Telephone and outpatient follow-ups were performed. RESULTS:Of 516 TAVI patients, 20 required ECS, and the bail-out surgery occurred less frequently with the increase in TAVI volume. The most common reason for conversion was left ventricular perforation (7/20, 35.0%). Thirty-day mortality was 35.0% in ECS patients. Kaplan-Meier survival curves showed that the cumulative survival rate was 65.0% at 1 year, 50.1% at 5 years in all ECS patients, and 77.1% at 5 years in patients who survived over 30 days after conversion. CONCLUSION:Although the bail-out operation was performed immediately after TAVI abortion, ECS still associated with high 30-day mortality. The long-term survival benefit was seen in patients surviving from bail-out surgery. An experienced TAVI team is of crucial importance in avoiding ECS-related life-threatening complications and providing effective salvage surgery.

Purpose: The dilation of proximal arch (PArc) was suspected to develop as a result of valve-related hemodynamics or in consequence to the upward extension of the ascending aorta (AAo) dilation. We aimed to investigate the one that could be the possible contributing factor in patients with bicuspid aortic valve (BAV). Methods: All enrolled BAV patients underwent four-dimensional flow magnetic resonance imaging. Contour-averaged circumferential wall shear stress (WSScirc,avg) and the diameter of the middle of AAo (mid-AAo) were compared between the patients with and without PArc dilation. Additionally, we analyzed the correlation between WSScirc,avg and aortic diameter at PArc section, as well as the correlation between the diameter of mid-AAo and that of PArc. Results: No significant difference was observed in WSScirc,avg at PArc section between the patients with and without PArc dilation (P=.621). However, the diameter of mid-AAo in the patients who suffered PArc dilation was higher than those without it (P=.007). In addition, the aortic diameter did not correlate with the WSScirc,avg at PArc level (R=-0.068, P=.701). The correlation was observed between PArc diameter and mid-AAo diameter (R=0.521, P=.002). Conclusion: Hemodynamics may not contribute to the development of PArc dilation. PArc diameter correlated with mid-AAo diameter, indicating PArc dilation may be secondary to the upward extension of AAo dilation. The influence of AAo dilation extending upward could be treated by AAo replacement; hence, a selective approach to transverse PArc replacement might be appropriate.

Background: Valve-related hemodynamics and intrinsically regulated matrix proteases are 2 determined pathogenetic factors associated with medial elastin degeneration in bicuspid aortopathy. This study analyzed the association between elastic fiber deterioration and the 2 pathogenetic factors in ascending and root morphotypes, aiming to elucidate the etiological heterogeneity between the 2 morphotypes. Methods: Four-dimensional flow cardiac magnetic resonance was used to measure the regional wall shear stress (WSS) on the ascending aorta, and matrix metalloproteinase (MMP) expression was assessed by immunoblotting. After histopathology analysis of aortic tissue, we assessed whether elevated regional WSS and increased MMP expression corresponded with medial elastin thinning. Results: Increased regional WSS corresponded with medial elastin thinning in both morphotypes. Increased expression of different MMP isoforms corresponded with medial elastin degeneration in bicuspid aortopathy. The significantly increased expression of MMP-2 corresponded with a decrease of elastic fiber thickness in the ascending morphotype (P = .046), whereas elastic fiber thinning was associated with high levels of MMP-3 expression (P = .012) in the root morphotype. No association was observed between regional WSS and MMP expression. Conclusion: There is no difference in the effect of valve-related hemodynamics between ascending and root morphotype, and MMPs are not involved in the process of elastic fiber degeneration induced by increased WSS. The increased expression of different MMP isoforms was observed in the context of elastic fiber degeneration between the 2 morphotypes, implying that heterogeneity between them is revealed in the different intrinsic pathway of medial elastin degradation.

PURPOSE:Our study aimed to investigate the potential pathogenetic theories of different phenotype prevalence in bicuspid aortopathy.METHODS:A total of 407 bicuspid aortic valve (BAV) patients with aortic dilation were retrospectively reviewed. Association was determined between aortic valve lesion types and aortic configurations to confirm the homogeneous BAV subsets, and then, dominance analysis was used to evaluate the relative importance of two components of aortic valve lesion (BAV phenotype and valvular dysfunction) that associated with aortic configurations in each subgroup.RESULTS:Dominance analysis showed that Type-1 LR was the dominant contributor (79.0% and 79.6%) associated with the higher prevalence of the dilation of aortic root (AoR) and ascending aorta (AAo) in BAV patients with Type-1 LR and aortic regurgitation (AR) or aortic stenosis (AS) + AR. However, AS was the main contributor (60.0%) associated with the raised incidence of the dilation of AAo and proximal aortic arch (PArc) in Type-0 LAT and AS.CONCLUSIONS:Different dominant pathogenetic theory determined the phenotype of BAV aortopathy. In patients of Type-1 LR with AR, inherent disposition is mainly responsible for the higher frequency of AoR dilation. Valve-related hemodynamics determined greater prevalence of the dilation of AAo and PArc in patients of Type-0 LAT with AS.

Purpose: Primary benign right ventricular tumours are rare lesions with variegated histological types. In this study, we describe our single-centre surgical experience with primary benign right ventricular tumours.

Purpose: Transcatheter heart valve (THV) dislocation during transcatheter aortic valve implantation (TAVI) is a rare but serious complication. In this study, we presented a method of preventing left ventricular embolism utilising a novel positioning element of the J-Valve System, and revealed the mid-term follow-up results of patients who experienced this acute complication.

1The long process of thin-walled burning barbecue net is simulated with mold filling and solidification process based on ProCAST software. The result shows that massive shrinkages consist in interior of the thin-walled baking net. According to the simulation result that by redesigning the structure of the pouring system, the optimized scheme can effectively reduce the number of shrinkages, so we can produce casting to meet the requirements. INTRODUCTION In recent years, with the vigorous development of stainless steel and high alloy steel precision casting technology, the higher quality requirements, the valve and the guide vanes and other structural components are used in precision casting to improve mechanical performance and surface quality of the casting [1]. However, because of the traditional casting is mainly manual work, the technology is relatively mature in size and lighter weight production, but for the production of baking net which has large complex structure with internal metallurgical quality and surface smoothness have high requirements and casting technology is difficult [2]. Therefore, how to autonomously, domestically and largely product such key casting, becoming a major issue in the national baking equipment manufacturing industry. The application of numerical simulation in casting is very extensive at present. The numerical simulation technology not only can simulate the casting solidification process, temperature field, and defects, but also can reduce the development cycle, reduce the cost and save the labor [3-6]. In this paper, the numerical simulation of the mold filling and solidification process of the thin-wall baking is carried out based on the ProCAST software, and the improvement measures are put forward in order to solve the problem of shrinkage and improve the qualified rate of the products. Yuling Hu1, a, Donghong Wang 1, b, Shumei Liu1,c, He Li1,d, Aohan Wang1, e, Fei Li2,f, 1School of Materials Engineering, Shanghai University of Engineering Science, Shanghai, 201620, China 2State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, China a2315417228@qq.com, bwdh@sues.edu.cn, c sgwy99999@163.com, dlihe2719@126.com, erjx002@sues.edu.cn, flfei@sjtu.edu.cn

In this paper, the preparation and organization performance of thermal barrier coatings (TCBs) on the surface of titanium were studied experimentally. Nanostructured 8 wt% yttria partially stabilized zirconia coatings were deposited by air plasma spraying. The microstructure of nanostructured and the conventional coating was studied after laser remelting. It has shown that formed a network of micro-cracks and pits after laser remelting on nanostructured coatings. With the decrease of the laser scanning speed, mesh distribution of micro cracks was gradually thinning on nanostructured coatings. Compared with conventional ceramic layers, the mesh cracks of nanostructured coating is dense and the crack width is small.

The water based high temperature lubricant for slide plates was prepared using high purily flake graphite micro powder as starting material, deionized water as disperse medium, adding organic and inorganic binders as well as surfactant, defoamng agent and antioxidants, then ball mill mixing. The effects of various antioxidants (B 4C micro powder, SiC micro powder, h-BN micro powder, TiB 2 micro powder and Si micro powder, respectiyely) as well as their additions on the antioxidation of the lubricant at high temperatures were studied. The lubricating property of the prepared lubricant was compared with the imported lubricant from Japan at different temperatures (20-800 °C). The resuits show that:1) the lubrioant with 3 mass% of h-BN performs the best antioxidation at high temperatures;2) the prepared lubricant performs better lubricating property at high temperatures (200-800 °C) than that from Japan;3) the SEM photos show that the prepared lubricant has smaller graphite, consequently better bonding strength, antioxidation and abrasion resistance than that from Japan -A) during practical application, the prepared ubricant coating on the slide plate can be used for 4-5 cycles, which is simlar to that of the imported lubricant.