Interference mechanism of trailing edge flap shedding vortices with rotor wake and aerodynamic characteristics

A robust Reynolds-Averaged Navier-Stokes(RANS)based solver is established to predict the complex unsteady aerodynamic characteristics of the Active Flap Control(AFC)rotor.The complex motion with multiple degrees of freedom of the Trailing Edge Flap(TEF)is analyzed by employing an inverse nested overset grid method.Simulation of non-rotational and rotational modes of blade motion are carried out to investigate the formation and development of TEF shedding vortex with high-frequency deflection of TEF.Moreover,the mechanism of TEF deflection interference with blade tip vortex and overall rotor aerodynamics is also explored.In nonrotational mode,two bundles of vortices form at the gap ends of TEF and the main blade and merge into a single TEF vortex.Dynamic deflection of the TEF significantly interferes with the blade tip vortex.The position of the blade tip vortex consistently changes,and its frequency is directly related to the frequency of TEF deflection.In rotational mode,the tip vortex forms a helical structure.The end vortices at the gap sides co-swirl and subsequently merge into the concentrated beam of tip vortices,causing fluctuations in the vorticity and axial position of the tip vortex under the rotor.This research concludes with the investigation on suppression of Blade Vortex Interaction(BVI),showing an increase in miss distance and reduction in the vorticity of tip vortex through TEF phase control at a particular control frequency.Through this mechanism,a designed TEF deflection law increases the miss distance by 34.7%and reduces vorticity by 11.9%at the target position,demonstrating the effectiveness of AFC in mitigating BVI.

Influence of Flap Parameters on the Aerodynamic Performance of a Wind-Turbine Airfoil

A numerical method has been used to analyze the flow field related to a NACA 0015 airfoil with and without a flap and assess the influence of the flap height and angle on the surface pressure coefficient,lift coefficient,and drag coefficient.The numerical results demonstrate that the flap can effectively improve the lift coefficient of the airfoil;however,at small attack angles,its influence is significantly reduced.When the angle of attack exceeds the critical stall angle and the flap height is 1.5%of the chord length,the influence of the flap becomes very evident.As the flap height increases,the starting point of the separation vortex gradually moves forward and generates a larger wake vortex.Optimal aerodynamic characteristics are obtained for 1.5%(of the chord length)flap height and a 45°flap angle;in this case,the separation vortex is effectively reduced.

两起波音737 MAX空难的致因分析:基于人—自动化交互的FLAP模型

两起波音737 MAX飞机坠毁事故的调查认为,MACS存在致命设计缺陷是导致两起空难的直接原因。MACS的运行逻辑及其行为脱离了机组对波音737系列飞机操控系统的理解,因此两起空难是典型的人—自动化交互失败的案例。FLAP模型有助于研究者以自上而下的、通用化的方法来模拟现今商业运输飞机中与自动化系统相关的问题,利用FLAP模型可以逆向回溯两起空难的成因:除了MACS设计不良之外,波音公司和FAA未遵守航空安全文化是造成两起事故的深层次原因。

Global hotspots and future directions for drugs to improve the skin flap survival: A bibliometric and visualized review

Skin flaps are frequently employed in plastic and reconstructive surgery to address tissue defects.However,their low survival rates remain a challenge,attributed to vascular crisis and necrosis.Despite numerous studies investigating drugs to alleviate flap necrosis,a comprehensive analysis of the research trend in this critical area is lacking.To gain a deeper understanding of the current status,research focal points,and future trends in drugs aimed at enhancing flap survival,a thorough retrospective analysis is imperative.This study aims to employ bibliometric methods to scrutinize the evolution,mechanisms,and forthcoming trends of drugs targeting flap survival improvement.Using VOSviewer software,we quantitatively and visually depict 1)annual temporal trends in the number of documents and citations;2)national/regional publications and their collaborations;3)institutional and authors’contribution;4)journal contribution and relevance;and 5)analysis of research hotspots and directions derived from keywords.Ultimately,we discussed the prospects and challenges of future advances and clinical translation of drugs designed to enhance skin flap survival.In conclusion,the field of pharmacology dedicated to improving skin flap survival is expanding,and this study aims to offer a fresh perspective to promote the advancement and clinical application of such drugs.

Nasal flap preservation in endoscopic dacryocystorhinostomy for nasolacrimal duct obstruction

AIM:To compare surgical outcomes between the conventional endoscopic dacryocystorhinostomy(DCR)and a modified endoscopic DCR for the treatment of nasolacrimal duct obstruction(NLDO),and evaluate factors associated with the surgical success rate.METHODS:Medical records of patients who underwent primary DCR surgery between January 2016 and July 2020 at the Otorhinolaryngology Department of Eye and Ear International Hospital,Lebanon were reviewed.RESULTS:The study group consisted of 50 consecutive modified endoscopic DCR and the control group consisted of 138 consecutive conventional endoscopic DCR.The success rates at 1y were 98.0%(49 out of 50)for modified DCR,significantly higher compared to 84.8%(117/138)for the conventional DCR;there was no significant difference in the success rate throughout the years in terms of both surgical techniques.The modified surgery vs traditional[adjusted odds ratio(aOR)=14.96]and having an adjunctive septoplasty surgery vs not(aOR=3.99)were significantly associated with higher odds of success.CONCLUSION:Mucosal flap preservation and apposition shows significant improvement in the surgical success rate.Moreover,there is no statistically significant difference found in terms of complication rate and mean operative time between the conventional and the modified techniques.

When the Combination of a Chinese Flap and Dufourmentel Makes It Possible to Treat a Hopeless Case of Squamous Cell Carcinoma of the Upper Lip

Cancers of the lip are the leading cause of labial defects, and treatment is essentially surgical. The success of a repair is assessed by two essential criteria: The functional character of the lip (restoration of continence allowing feeding) and the aesthetic quality of the repair. However, for many patients from countries whose medical infrastructure does not allow them to undertake complex reconstructions locally, medical transfers represent their only chance of treatment. The aim of this article is to share with you an extreme clinical case of labial reconstruction, the management of which was a real challenge, using two major flaps: the free ante-brachial flap and the DUFOURMENTEL-type bi-pediculated scalp flap.

Management of Square Carcinoma of the Lower Lip Using Camille-Bernard Flap under Local Anesthesia: When Constraints Dictate Our Attitude

Introduction: Squamous cell carcinomas of the lip essentially pose a therapeutic management problem. In the West, their treatment is done under general anesthesia and follows the classic rules of oncology. In our context of exercise, we sometimes have a different attitude dictated by various constraints. Observation: 55-year-old patient with no notable history, seen in consultation for a very large ulcerative-budding lesion on the right 2/3 of the lower lip with mucocutaneous involvement without lymph node findings found on examination. Faced with this suspicious lesion and the patient’s financial difficulties, we decided to operate under local anesthesia to remove this tumor. The oncological excision was followed by immediate plasty using a Camille-Bernard flap with a good immediate aesthetic and functional result and postoperative day 7. The patient was unable to take his surgical specimen to anatomy-pathology and was lost to follow-up due to lack of financial resources. On anatomo-pathological analysis of the surgical specimen, the margins were healthy with confirmation of squamous cell carcinoma (anapathological reading made for scientific interest). Discussion: The particular mentality of certain patients and their difficult financial conditions push us to have an unconventional therapeutic attitude in oncology, but which nevertheless makes it possible to resolve certain problems that we often face. Local anesthesia is possible and realistic in cases like ours and the results can be acceptable and life-saving.

Impact of Blade-Flapping Vibration on Aerodynamic Characteristics of Wind Turbines under Yaw Conditions

Although the aerodynamic loading of wind turbine blades under various conditions has been widely studied,the radial distribution of load along the blade under various yaw conditions and with blade flapping phenomena is poorly understood.This study aims to investigate the effects of second-order flapwise vibration on the mean and fluctuation characteristics of the torque and axial thrust of wind turbines under yaw conditions using computational fluid dynamics(CFD).In the CFD model,the blades are segmented radially to comprehensively analyze the distribution patterns of torque,axial load,and tangential load.The following results are obtained.(i)After applying flapwise vibration,the torque and axial thrust of wind turbines decrease in relation to those of the rigid model,with significantly increased fluctuations.(ii)Flapwise vibration causes the blades to reciprocate along the axial direction,altering the local angle of attack and velocity of the blades relative to the incoming wind flow.This results in the contraction of the torque region from a circular shape to a complex“gear”shape,which is accompanied by evident oscillations.(iii)Compared to the tangential load,the axial load on the blades is more sensitive to flapwise vibration although both exhibit significantly enhanced fluctuations.This study not only reveals the impact of flapwise vibration on wind turbine blade performance,including the reduction of torque and axial thrust and increased operational fluctuations,but also clarifies the radial distribution patterns of blade aerodynamic characteristics,which is of great significance for optimizing wind turbine blade design and reducing fatigue risks.

Evaluation of the versatility of perforators-enhanced rhomboid flap technique for ischial sores reconstruction

Background: Prolonged pressure on the skin known as pressure sores, can cause frequent injuries to the skin and underlying tissues. However, several prevention approaches, including non-surgical and surgical management,are available. In flap surgery for pressure sores, a variety of flap types may be used;each offers certain benefits and some incidences of complications and recurrence. This study evaluated the versatility of the perforatorenhanced rhomboid flap technique for ischial sore construction.Methods: This prospective study was conducted in the Plastic Surgery Department of Fayoum University Hospital.The perforator-enhanced rhomboid flap technique was employed in 20 patients with ischial pressure sores who failed to respond to conservative treatment. A proper history was obtained and a preoperative arterial duplex was performed to determine the site of the prominent perforators for their preservation at the base of the flap.Postoperative follow-ups and evaluations were performed.Results: The mean age of the study group was 43.7 ± 13.1, ranging from 19 to 65 years. Moreover, 80% of the participants were males while 20% were female. The main etiology of the sores was paraplegia in 45% of cases.The mean surface area of sores was 24.8 ± 6.3 cm2. In 75% of cases, the color match of the flap was rated as excellent. Similarly, 70% of the patients rated flap thickness as excellent. In 55% of the cases, the scar appearance was deemed excellent. Overall satisfaction was reported as excellent by 40% of the patients, while only 5% reported poor satisfaction. Approximately, 10% of the cases were identified with seroma, and 30% had wound dehiscence of a mean size of 1.33 ± 0.98 cm and required around 6.8 ± 1.9 weeks to heal.Conclusion: The perforator-enhanced rhomboid flap technique is a versatile method for reconstructing ischial pressure sores owing to its technical ease, short operative time, reliable vascularity, aesthetic outcome, matching skin color, and short recovery time. The main limitations include large defects with large surface areas, lack of a nearby donor site for a rhomboid flap, and scarring from prior procedures around the sore.

Adaptability of bipedicled scalp advancement flap for coverage of huge scalp defects after tumor resection

Background:Several reconstructive techniques have been used to reconstruct scalp defects.Numerous researchers have studied the utilization of bipedicled scalp advancement flaps for scalp defect coverage.In this study,we will assess the adaptability of a bipedicled scalp advancement flap for coverage of huge scalp defects after tumor resection.Methods:This study was performed at the Plastic Surgery Department,Fayoum University Hospital,on 20 patients with huge scalp tumors treated by adequate excision and reconstructed using a bipedicled scalp advancement flap from December 2021 to July 2023.Results:The study was conducted on 20 patients:16(80%)were men and 4(20%)were women presenting with large scalp tumors.The mean age was 57.4 years(33-68 years).The sites of the tumors were 10(50%)occipital,6(30%)parietal,and 4(20%)parieto-occipital.No major complications occurred postoperatively,and the bipedicled flaps survived well in all cases,with no necrosis.Conclusion:Huge scalp defects after tumor resection can be safely reconstructed with a large versatile bipedicled advancement scalp flap,either transversely or longitudinally oriented,with favorable functional results and accepted aesthetic results,apart from the alopecic area over the grafted donor site,which can be treated by tissue expansion if desired later.

Pedicled abdominal flap using deep inferior epigastric artery perforators for forearm reconstruction: A case report

BACKGROUND Pedicled abdominal flaps are a widely used surgical technique for forearm reconstruction in patients with soft tissue defects.However,some drawbacks include restricted flap size,partial flap loss,and donor-site morbidity.To address these concerns,we present a case of a pedicled abdominal flap using the deep inferior epigastric artery perforators(DIEP)for forearm reconstruction in a patient with a large soft tissue defect.CASE SUMMARY A 46-year-old male patient was admitted to our hospital with forearm injury caused by a pressing machine.A 15 cm×10 cm soft tissue defect with complete rupture of the ulnar side structures of the forearm was found.One week after orthopedic management of the neurovascular injury and fractures using the first stage of Masquelet technique,the patient was referred to the plastic and recon-structive surgery department for wound coverage.Surgical debridement and negative-pressure wound therapy revealed a 20 cm×15 cm soft tissue defect.A pedicle abdominal flap with the DIEP was used to cover the defect.Three weeks later,the flap was detached from the abdomen,and the abdominal defect was directly closed.Subsequently,the second stage of Masquelet technique was performed at the fracture site at week 10.Finally,all donor and recipient sites healed without complications,such as flap dehiscence,infection,hematoma,or necrosis.Fracture site osteosynthesis was achieved without complications.CONCLUSION Pedicled abdominal flap using the DIEP provides a reliable option for forearm reconstruction in patients with large soft tissue defects.

Using Mustardé Flap for Reconstruction of a Traumatic Facial Injury: Case Report

Flaps become the first option when primary closure is not possible, using them to reduce the tension in the closure, as well as improving the texture and color, which ends in having a better aesthetic outcome. The Mustardé flap is a flap used for the cheek and lower eye lid defects. We present a 26-year-old male with an avulsive wound in the right maxillary region, with no bone injuries, taken to the operative room performing a Mustardé Flap for reconstruction of the defect area. Patient completed a 7-day antibiotic regimen, using non-steroid anti-inflammatories for pain, wound cleaning and flap hydration with mineral oil, subsequently having an adequate clinical and aesthetic evolution. Conclusion: The Mustardé flap can be a useful pedicled flap for the reconstruction of full-thickness defects.

Lateral circumflex femoral artery perforator flap for the reconstruction of head soft tissue defects:Cross-region venous anastomosis

Background:Owing to its unique characteristics,the lateral circumflex femoral artery perforator(LCFAP)flap is often preferred for repairing head wounds with exposed skulls.However,given the vascular distribution in the head,particularly the veins,can lead to postoperative complications such as venous congestion of the flap.The rates of vascular exploration and necrosis in these flaps are significantly higher than in other body regions.Therefore,it is crucial to identify a safe and effective method for venous anastomosis of free flaps in the head region.Methods:This retrospective case series study included 10 patients with large head soft tissue defects treated at the Burn and Plastic Surgery Department of the Affiliated Hospital of Zunyi Medical University from January 2020 to December 2022.The head defects were reconstructed using LCFAP flaps,with flap veins anastomosed to the external jugular vein in the neck,either directly or via a bridging technique.Results:Among the 10 adult patients with massive head wound defects,7(70%)were men.The patients’mean age was 53.0 years(48–59 years).The wound defects were caused by trauma in 6(60%)patients and by tumors in 4(40%)patients.Postoperatively,no significant complications occurred,and all LCFAP flap survived without necrosis.Conclusion:The descending branch of the LCFAP flap effectively repairs massive head wound defects.The venous anastomosis method for this flap is associated with a low incidence of venous complications and a high patency rate,making it a clinically valuable reference.

Thrust Optimization of Flapping Wing via Gradient Descent Technologies

The current work aims at employing a gradient descent algorithm for optimizing the thrust of a flapping wing. An in-house solver has been employed, along with mesh movement methodologies to capture the dynamics of flow around the airfoil. An efficient framework for implementing the coupled solver and optimization in a multicore environment has been implemented for the generation of optimized solutionsmaximizing thrust performance & computational speed.

Unusual Anterolateral Fascio Cutaneous Tight Flap for Extremity Soft Tissue Reconstruction

Soft tissue sarcoma is rare neoplasms that affect mainly the extremities. Surgery is the mean treatment and the resection results in extensive muscle and skin loss. The anterolateral tight flap is a good option for sarcomas arising in knees, superior third of legs and the medial face of thigh. The anatomy knowledge and the multidisciplinary approach is very important for a successful reconstruction. The authors report a successful case treated with the anterolateral tight flap and a literature review.

Utility of Preoperative Positron Emission Tomography (PET) in Localizing Perforator Vessels of Anterolateral Thigh Free Flap

Objectives: The anterolateral thigh (ALT) flap is often considered the workhorse in soft tissue reconstruction of head and neck defects secondary to trauma, infection, or tumor resection. Despite its many advantages, ALT flaps have been criticized due to variability in vasculature, which may result in inadequate or non-existent perforators. This retrospective study aims to investigate the utility and validity of positron emission tomography (PET) scan to identify the location and characteristics of perforators to the ALT flap. Methods: We performed a 10-year retrospective review of ALT flaps at our institution to identify patients with preoperative PET scans available for analysis. Three reviewers (attending physician, fellow, and resident) were asked to identify the number, location, and characteristics (myocutaneous versus septocutaneous) of ALT perforators on imaging, and reviewer agreement was assessed. Results were then compared to available operative data. Results: One hundred twenty-one patients were identified who underwent ALT free flap surgery. Thirty-eight preoperative PET scans were identified for review. At least one perforator was identified in 92.1% of scans. Agreement percentages regarding the number of perforators ranged from 53% - 61% whereas agreement regarding the location of a single perforator ranged from 79% - 90%. However, reviewers did not agree regarding the type of perforator, with agreement ranging from 34% - 53%. Poor agreement was observed when compared to intraoperative data, with the number of perforators ranging from 26% - 34% and the type of perforator 11% - 24%. These findings are likely due to insufficient data available in operative reports. Conclusion: Although initial studies suggest that PET scan shows promising evidence to support the capacity to preoperatively identify ALT perforators, future prospective studies are warranted to fully validate these findings.

Sternocleidomastoid flap for reconstruction of tongue small cell carcinoma: A case report

BACKGROUND The management of tongue carcinoma is excision and radical neck dissection followed with reconstruction.This is a case report of a patient with tongue squamous cell carcinoma(SCC)who underwent the procedure with sternocleidomastoid(SCM)flap reconstruction.CASE SUMMARY A 52-year-old woman without smoking history complained tongue ulcer since 3 years ago.Based on the histopathological examination,the patient was diagnosed with T2N2M0 right tongue SCC and underwent wide excision of tumor;right mandibular;neck dissection and were reconstructed with SCM flap.CONCLUSION SCC of the tongue requires wide excision and dissection of the neck and mandible if infiltration into the surrounding lymph nodes has been found.The SCM flap reconstruction could be used post-surgery.

带感觉神经游离股前外侧皮瓣在口腔癌术后缺损修复重建中的临床应用

目的:探讨带感觉神经游离股前外侧皮瓣在口腔癌术后缺损修复重建中的临床效果。方法:选取南充市中心医院口腔颌面外科2020年9月-2022年9月采用带感觉神经的游离股前外侧皮瓣修复重建口腔癌扩大切除后组织缺损的患者16例,根据原发灶切除后组织缺损的大小并结合皮瓣收缩率设计皮瓣,长5~10 cm,宽4~8 cm。皮瓣制备的同时携带股外侧皮神经,待供、受区动静脉吻合完成后再行股外侧皮神经与受区感觉神经端端吻合,供瓣区创面减张后直接拉拢缝合。术后随访12~24个月,对术后效果进行评价。结果:16例口腔癌缺损采用带感觉神经游离股前外侧皮瓣修复术后均成活,皮瓣色泽、形态、质地优良,咀嚼、吞咽、言语功能良好,感觉功能恢复S0级2例,S1级4例,S2级6例,S3级2例,S3+级2例,游离皮瓣无1例发生溃疡。其中1例右舌中-高分化鳞癌(T3N1M0),术后13个月发生全身远处转移后死亡。结论:带感觉神经的游离股前外侧皮瓣修复重建口腔癌术后缺损,其外形及功能恢复良好,在一定程度上能恢复皮瓣感觉功能。

改良巩膜瓣制作在青光眼小梁切除术中的疗效观察

目的探讨改良巩膜瓣制作及缝合方法在青光眼小梁切除术中的疗效。方法纳入摩洛哥拉西迪亚大区眼科医院2021年4月—2022年9月收治的青光眼患者98例(98只眼),其中双眼发病8例以临床症状相对较重眼入组,随机分为观察组50例(50只眼)和对照组48例(48只眼)。其中观察组术中采用改良的巩膜瓣制作方法,对照组术中采用常规矩形巩膜瓣手术。记录2组患者的手术时间,术后7 d平均眼压、早期浅前房形成情况及术后14 d功能性滤过泡情况,并进行比较。结果(1)手术时间:观察组平均手术时间低于对照组,差异有统计学意义(t=7.601,P=0.000)。(2)眼压:2组术后7 d平均眼压比较,差异无统计学意义(P>0.05)。(3)浅前房形成情况:观察组术后7 d发生轻度及中度浅前房2例(4.00%),而对照组为10例(20.83%),差异有统计学意义(χ^(2)=8.255,P=0.016)。(4)功能性结膜滤过泡形成情况:2组术后14 d形成功能性滤过泡数量比较,差异无统计学意义(P>0.05)。结论青光眼小梁切除术中采用改良巩膜瓣制作方法,可有效减少手术损伤,缩短手术时间,更好地调控房水滤过率,减小缝线的局部刺激,降低术后浅前房的发生率。

肿瘤术后唇及唇周缺损的分类与功能修复重建

唇肿瘤手术可能导致唇和唇周缺损,目前缺乏明确的唇肿瘤切除术后唇和唇周区域缺损分类分型与缺损修复重建原则。笔者根据唇缺损的范围将唇缺损分为唇部分缺损、唇全层缺损和唇全层伴唇周缺损3大类。其中唇部分缺损包括红唇缺损、唇皮肤缺损、唇黏膜缺损和唇洞穿缺损4型;唇全层缺损包括小半唇、半唇、次全唇缺损和全唇缺损4型;唇全层伴唇周缺损包括口角颊洞穿性缺损、全唇颏缺损和全唇鼻缺损3型。唇肿瘤根治性手术的同时,唇和唇周区域不同类型缺损原则上是同期修复的。缺损修复方法包括一期缝合、皮肤或黏膜移植、局部皮瓣、区域皮瓣、带蒂皮瓣、游离皮瓣和同种异体真皮基质修复等方法;也可以结合多个组织瓣进行修复重建。其中,腹侧舌肌黏膜瓣是修复重建红唇缺损的理想组织瓣;Abbe-Estlander瓣是唇缺损修复重建非常重要的技术;双侧颏神经血管V-Y岛状推进皮瓣与舌黏膜瓣联合重建全下唇缺损,方法可靠效果好;修复唇口角颊洞穿性缺损可选用Estlander瓣,折叠延长锁骨上岛状皮瓣或折叠面-颏下动脉岛状瓣;全唇颏或全唇鼻缺损等特大型缺损需要用胸大肌瓣,斜方肌肌皮瓣或游离组织瓣甚至联合多瓣进行修复。本文提出了唇肿瘤术后唇及唇周缺损的分类和分型,较系统地阐述了唇及唇周缺损功能修复重建的方法,对临床具有一定的指导和推广应用价值。