Functional Dependence of IM and HV Angle in Hallux Valgus Deformity before and after Operative

Hallux valgus is a relatively common and multifaceted complex deformity of the front part of the foot. It is the result of multiple effects of innate (endogenous) and exogenous etiological factors with different degrees of influence. The degree of hallux valgus deformity is usually assessed by radiological values of hallux valgus (HV) and intermetatarsal (IM) angles. The aim of the paper is to justify the definition of hallux valgus deformity as a function of one angle, (HVA or IMA), and then to determine the functional connection and the most suitable function equalizing the values of the angles IMA and HVA. As hallux valgus is a double angulation deformity, the analytically determined connection between the HVA and IMA angles reduces the study of the deformity to the study of function with one argument, and makes the analysis of deformity changes before and after operative treatment simpler. For the determined connections between the angles, the values of linear proportionality coefficients and regression coefficients of corresponding linear functions of analytical equalization of the value of the IM angle and the degree of deformity for a given value of the HV angle were experimentally determined. The obtained results were checked on a sample of 396 operatively treated hallux valgus deformities. The presented analytical approach and the obtained functional links of IMA and HVA enable quantitative observation of the change in the degree of deformity based on the radiologically determined value of these angles, and the established nonlinear function will be useful for evaluating the expected value of the IM angle and the degree of deformity based only on the measured value of the HV angle. .

Skin color of Chinese women across different regions of China:An analysis based on both individual typology angle and hue angle

Skin color is considered an important beauty standard for women in China.The typical tool for skin color measurement,individual typology angle(ITA),was developed based on Caucasian skin features.The ITA effectively measures the brightness of facial skin,which is traditionally associated with beauty in Caucasian women.However,in Chinese women,whiteness is not the only determinant of skin esthetics,and other elements such as“yellowness”and“redness”are also important considerations.Thus,the hue angle system was developed based on the skin features of Chinese women,whose skin is typically on the“yellow-red”spectrum.Studies examining the skin color of Chinese women based on both the ITA and hue angle should be carried out.The skin colors of 4500 women aged 18–45 years across five different regions of China were measured using both the ITA and hue angle systems.The relationship of the“red pigment and melanin content”with the“brightness and redness of skin color”was also examined.Further,the different skin types of women across different regions were identified.Measurements based on the ITA system reveal a saddle-shaped distribution of skin brightness among Chinese women across five different regions,with skin brightness being high in the eastwest regions and low in the north-south regions.The ITA and hab values are not consistent in individual women,and thus,both need to be considered when evaluating skin color.Additionally,no correlation between the skin’s red pigment and melanin content and the skin’s ITA and hab values is identified.This study provides skin color data based on both the ITA and hue angle systems.The findings show that skin ITA/hab values cannot simply be explained by the red pigment/melanin content of the skin.Given the distribution of skin types across different regions of China,whitening ingredients causing little to no irritation should be used to formulate whitening cosmetics.

Clinical Application of Cataract Ultrasonic Emulsification Combined with Atrial Angle Segmentation in the Treatment of Primary Angle-Closure Glaucoma

Objective:To evaluate the therapeutic effect of cataract ultrasonic emulsification(PE)combined with atrial angle separation(CSS)for primary angle-closure glaucoma(PACG).Methods:78 patients with PACG admitted to the hospital between October 2021 and October 2023 were selected and grouped by randomized numerical table;39 cases were counted in the observation group and selected PE combined with CSS surgery;39 cases were counted in the reference group and selected PE combined with trabeculectomy and the total effective rate,the state of the atrial angle,the clinical indexes,the degree of ocular symptoms,and the complication rate were compared.Results:The total effective rate of the observation group was higher than that of the reference group,and the percentage of the wide atrial angle of the atrial angle status was higher than that of the reference group;3 months after the operation,the logarithm of the minimum angle of resolution(Log MAR)and intraocular pressure of the observation group was lower than that of the reference group,and the central anterior chamber depth(ACD)was greater than that of the reference group;the scores of the degree of ocular symptoms of the observation group were lower than that of the reference group,and the rate of complication was lower than that of the reference group(P<0.05).Conclusion:PE combined with CSS surgical treatment for PACG patients can improve the efficacy of treatment,improve the state of the patients’atrial angles,and restore the ocular function indexes.It can alleviate the ocular symptoms as soon as possible and has a high surgical safety.

Fine mapping of two recessive genes TaFLA1 and TaSPL8 controlling flag leaf angle in bread wheat

Flag leaf angle is one of the key target traits in high yield wheat breeding.A smaller flag leaf angle reduces shading and enables plants to grow at a higher density,which increases yield.Here we identified a mutant,je0407,with an 84.34%-89.35%smaller flag leaf angle compared with the wild type.The mutant also had an abnormal lamina joint and no ligule or auricle.Genetic analysis indicated that the ligule was controlled by two recessive genes,which were mapped to chromosomes 2AS and 2DL.The mutant allele on chromosome 2AS was named Tafla1b,and it was fine mapped to a 1 Mb physical interval.The mutant allele on chr.2DL was identified as Taspl8b,a novel allele of TaSPL8 with a missense mutation in the second exon,which was used to develop a cleaved amplified polymorphic sequence marker.F3 and F4 lines derived from crosses between Jing411 and je0407 were genotyped to investigate interactions between the Tafla1b and Taspl8b alleles.Plants with the Tafla1b/Taspl8a genotype had 58.41%-82.76%smaller flag leaf angles,6.4%-24.9%shorter spikes,and a greater spikelet density(0.382 more spikelets per cm)compared with the wild type.Plants with the Tafla1a/Taspl8b genotype had 52.62%-82.24%smaller flag leaf angles and no differences in plant height or spikelet density compared with the wild type.Tafla1b/Taspl8b plants produced erect leaves with an abnormal lamina joint.The two alleles had dosage effects on ligule formation and flag leaf angle,but no significant effect on thousand-grain weight.The mutant alleles provide novel resources for improvement of wheat plant architecture.

Experimental Study on the Variation of Optical Imaging Characteristics with Zenith Angle due to Internal Solitary Waves in Sunglint

Internal solitary waves(ISWs)change the roughness of the sea surface,thus producing dark and bright bands in optical images.However,reasons for changes in imaging characteristics with the solar zenith angle remain unclear.In this paper,the optical imaging pattern of ISWs in sunglint under different zenith angles of the light source is investigated by collecting optical images of ISWs through physical simulation.The experiment involves setting 10 zenith angles of the light source,which are divided into area a the optical images of ISWs in the three areas show dark-bright mode,single bright band,and bright-dark mode,which are consistent with those observed by optical remote sensing.In addition,this study analyzed the percentage of the dark and bright areas of the bands and the change in the relative gray difference and found changes in both areas under different zenith angles of the light source.The MODIS and ASAR images display a similar brightness-darkness distance of the same ISWs.Therefore,the relationship between the brightness-darkness distance and the characteristic half-width of ISWs is determined in accordance with the eKdV theory and the imaging mechanism of ISWs of the SAR image.Overall,the relationship between them in the experiment is almost consistent with the theoretical result.

In situ calibrated angle between the quantization axis and the propagating direction of the light field for trapping neutral atoms

The recently developed magic-intensity trapping technique of neutral atoms efficiently mitigates the detrimental effect of light shifts on atomic qubits and substantially enhances the coherence time. This technique relies on applying a bias magnetic field precisely parallel to the wave vector of a circularly polarized trapping laser field. However, due to the presence of the vector light shift experienced by the trapped atoms, it is challenging to precisely define a parallel magnetic field, especially at a low bias magnetic field strength, for the magic-intensity trapping of85Rb qubits. In this work, we present a method to calibrate the angle between the bias magnetic field and the trapping laser field with the compensating magnetic fields in the other two directions orthogonal to the bias magnetic field direction. Experimentally, with a constantdepth trap and a fixed bias magnetic field, we measure the respective resonant frequencies of the atomic qubits in a linearly polarized trap and a circularly polarized one via the conventional microwave Rabi spectra with different compensating magnetic fields and obtain the corresponding total magnetic fields via the respective resonant frequencies using the Breit–Rabi formula. With known total magnetic fields, the angle is a function of the other two compensating magnetic fields.Finally, the projection value of the angle on either of the directions orthogonal to the bias magnetic field direction can be reduced to 0(4)° by applying specific compensating magnetic fields. The measurement error is mainly attributed to the fluctuation of atomic temperature. Moreover, it also demonstrates that, even for a small angle, the effect is strong enough to cause large decoherence of Rabi oscillation in a magic-intensity trap. Although the compensation method demonstrated here is explored for the magic-intensity trapping technique, it can be applied to a variety of similar precision measurements with trapped neutral atoms.

Experimental Study of Local Scour Around Four Piles Under Different Attack Angles and Gap Ratios

In an effort to investigate and quantify the patterns of local scour,researchers embarked on an in-depth study using a systematic experimental approach.The research focused on the effects of local scour around a set of four piles,each subjected to different hydromechanical conditions.In particular,this study aimed to determine how different attack angles—the angles at which the water flow impinges on the piles,and gap ratios—the ratios of the spacing between the piles to their diameters,influence the extent and nature of scour.A comprehensive series of 35 carefully designed experiments were orchestrated,each designed to dissect the nuances in how the gap ratio and attack angle might contribute to changes in the local scour observed at the base of pile groups.During these experimental trials,a wealth of local scour data were collected to support the analysis.These data included precise topographic profiles of the sediment bed around the pile groups,as well as detailed scour time histories showing the evolution of scour at strategic feature points throughout the test procedure.The analysis of the experimental data provided interesting insights.The study revealed that the interplay between the gap ratio and the attack angle had a pronounced influence on the scouring dynamics of the pile groups.One of the key observations was that the initial phases of scour,particularly within the first hour of water flow exposure,were characterized by a sharp increase in the scour depth occurring immediately in front of the piles.After this initial rapid development,the scour depth transitioned to a more gradual change rate.In contrast,the scour topography around the piles continuously evolved.This suggests that sediment displacement and the associated sculpting of the seabed around pile foundations are sustained and progressive processes,altering the underwater landscape over time.The results of this empirical investigation have significant implications for the design and construction of offshore multi-pile foundations,providing a critical reference for engineers and designers to estimate the expected scour depth around such structures,which is an integral part of decisions regarding foundation design,selection of structural materials,and implementation of scour protection measures.

An approach for determination of lateral limit angle in kinematic planar sliding analysis for rock slopes

Planar sliding is one of the frequently observed types of failure in rock slopes.Kinematic analysis is a classic and widely used method to examine the potential failure modes in rock masses.The accuracy of planar sliding kinematic analysis is significantly influenced by the value assigned to the lateral limit angleγlim.However,the assignment ofγlim is currently used generally based on an empirical criterion.This study aims to propose an approach for determining the value ofγlim in deterministic and probabilistic kinematic planar sliding analysis.A new perspective is presented to reveal thatγlim essentially influences the probability of forming a potential planar sliding block.The procedure to calculate this probability is introduced using the block theory method.It is found that the probability is correlated with the number of discontinuity sets presented in rock masses.Thus,different values ofγlim for rock masses with different sets of discontinuities are recommended in both probabilistic and deterministic planar sliding kinematic analyses;whereas a fixed value ofγlim is commonly assigned to different types of rock masses in traditional method.Finally,an engineering case was used to compare the proposed and traditional kinematic analysis methods.The error rates of the traditional method vary from 45%to 119%,while that of the proposed method ranges between 1%and 17%.Therefore,it is likely that the proposed method is superior to the traditional one.

Coupled DEM-FDM analyses of the effects of falling rock’s shape and impact angle on response of granular cushion and rock shed

Rock shed is an effective protection measure against rockfall.To investigate the influences of falling rock’s shape and impact angle on the impact effect of the cushioned rock shed,a modeling approach for a rock shed with a cushion layer using PFC-FLAC.The granular cushion is modeled as an aggregate of discrete non-cohesion particles,while the concrete plate and the beam are modeled as zones.The falling rock with different sphericities and impact angles is modeled as a rigid assembly.The numerical model is validated by comparing the simulation results with experimental and numerical results from previous literature.This model is applied to analyze the effects of rock shape and impact angle on the dynamic interaction effects between falling rock and cushioned rock shed,including the impact force,transmitted bottom force,penetration depth,and plate deflection.The numerical results show that the variation in the falling rock’s shape has different effects on the falling rock with different impact angles.These findings could support rock shed design by revealing the limitations of the assumptions in the past research,which may result in unsafe rock sheds for some rockfall cases.

Identification of the BTA8 gene reveals the contribution of natural variation to tiller angle in rice

Plant architecture is a collection of major agronomic traits that determines rice grain production,and it is mainly influenced by tillering,tiller angle,plant height and panicle morphology(Wang and Li 2006).Tiller angle is one of the critical components that determines rice plant architecture,which in turn influences grain yield mainly due to its large impact on plant density(Wang et al.2022).

Development of a DFN-based probabilistic block theory approach for bench face angle design in open pit mining

In open pit mining,uncontrolled block instabilities have serious social,economic and regulatory consequences,such as casualties,disruption of operation and increased regulation difficulties.For this reason,bench face angle,as one of the controlling parameters associated with block instabilities,should be carefully designed for sustainable mining.This study introduces a discrete fracture network(DFN)-based probabilistic block theory approach for the fast design of the bench face angle.A major advantage is the explicit incorporation of discontinuity size and spatial distribution in the procedure of key blocks testing.The proposed approach was applied to a granite mine in China.First,DFN models were generated from a multi-step modeling procedure to simulate the complex structural characteristics of pit slopes.Then,a modified key blocks searching method was applied to the slope faces modeled,and a cumulative probability of failure was obtained for each sector.Finally,a bench face angle was determined commensurate with an acceptable risk level of stability.The simulation results have shown that the number of hazardous traces exposed on the slope face can be significantly reduced when the suggested bench face angle is adopted,indicating an extremely low risk of uncontrolled block instabilities.

An improved algorithm based on equivalent sound velocity profile method at large incident angle

With the development of ultra-wide coverage technology,multibeam echo-sounder(MBES)system has put forward higher requirements for localization accuracy and computational efficiency of ray tracing method.The classical equivalent sound speed profile(ESSP)method replaces the measured sound velocity profile(SVP)with a simple constant gradient SVP,reducing the computational workload of beam positioning.However,in deep-sea environment,the depth measurement error of this method rapidly increases from the central beam to the edge beam.By analyzing the positioning error of the ESSP method at edge beam,it is discovered that the positioning error increases monotonically with the incident angle,and the relationship between them could be expressed by polynomial function.Therefore,an error correction algorithm based on polynomial fitting is obtained.The simulation experiment conducted on an inclined seafloor shows that the proposed algorithm exhibits comparable efficiency to the original ESSP method,while significantly improving bathymetry accuracy by nearly eight times in the edge beam.

Blade Wrap Angle Impact on Centrifugal Pump Performance:Entropy Generation and Fluid-Structure Interaction Analysis

The centrifugal pump is a prevalent power equipment widely used in different engineering patterns,and the impeller blade wrap angle significantly impacts its performance.A numerical investigation was conducted to analyze the influence of the blade wrap angle on flow characteristics and energy distribution of a centrifugal pump evaluated as a low specific speed with a value of 69.This study investigates six impellermodels that possess varying blade wrap angles(95°,105°,115°,125°,135°,and 145°)that were created while maintaining the same volute and other geometrical characteristics.The investigation of energy loss was conducted to evaluate the values of total and entropy generation rates(TEG,EGR).The fluid-structure interaction was considered numerically using the software tools ANSYS Fluent and ANSYSWorkbench.The elastic structural dynamic equation was used to estimate the structural response,while the shear stress transport k–ωturbulence model was utilized for the fluid domain modeling.The findings suggest that the blade wrap angle has a significant influence on the efficiency of the pump.The impeller featuring a blade wrap angle of 145°exhibits higher efficiency,with a notable increase of 3.76%relative to the original model.Variations in the blade wrap angle impact the energy loss,shaft power,and pump head.The model with a 145°angle exhibited a maximum equivalent stress of 14.8MPa and a total deformation of 0.084 mm.The results provide valuable insights into the intricate flow mechanism of the centrifugal pump,particularly when considering various blade wrap angles.

An improved positioning model of deep-seafloor datum point at large incidence angle

The inhomogeneous sound speed in seawater causes refraction of sound waves,and the elimination of the refraction effect is essential to the accuracy of underwater acoustic positioning.The raytracing method is an indispensable tool for effectively handling problems.However,this method has a conflict between localization accuracy and computational quantity.The equivalent sound speed profile(ESSP)method uses a simple sound speed profile(SSP)instead of the actual complex SSP,which can improve positioning precision but with residual error.The residual error is especially non-negligible in deep water and at large beam incidence angles.By analyzing the residual error of the ESSP method through a simulation,an empirical formula of error is presented.The data collected in the sailing circle mode(large incidence angle)of the South China Sea are used for verification.The experiments show that compared to the ESSP method,the improved algorithm has higher positioning precision and is more efficient than the ray-tracing method.

Suicide risk in juvenile open angle glaucoma patients

AIM:To investigate the association between juvenile open angle glaucoma(JOAG)and mental health among Koreans.METHODS:This study used nationally representative data from the 8th Korea National Health and Nutrition Examination Survey(KNHANES)2021.Glaucoma diagnosis followed the International Society of Geographical and Epidemiological Ophthalmology criteria based on glaucomatous structural defects,visual field defects,corrected vision,and intraocular pressure.As outcomes,suicidal behaviors,psychiatric counseling,and depression were evaluated through mental health questionnaires.Odds ratios(ORs)with 95%confidence intervals(CIs)were estimated using logistic regression models,adjusting for covariates.RESULTS:Among 7090 participants,3446 met the inclusion criteria for analysis,and 88(2.6%)were diagnosed with open angle glaucoma(OAG).After adjusting for age,sex,and best-corrected visual acuity(VA),participants with OAG were revealed to have significantly higher odds of suicidal behaviors(i.e.,ideation,planning,or attempts)compared with those without OAG(OR:2.70;95%CI:1.12-6.54;P=0.028).This association remained significant after further adjustments for socioeconomic status,lifestyle factors,and presence of chronic conditions(P=0.031 and 0.035,respectively).However,there was no significant difference for the other two outcomes,psychiatric counseling and depression.An age-stratified analysis revealed a stronger association between OAG and suicidal behaviors in younger JOAG participants(<40y)than in older OAG participants(≥40y;OR:3.80 vs 2.22;95%CI:0.79-18.22 vs 0.56-8.80,respectively).CONCLUSION:OAG patients show a higher risk of suicidal behaviors than those without glaucoma particularly in JOAG patients.

MP-3 microperimeter in early primary open angle glaucoma with a new pattern

AIM:To investigate macular microperimetry in patients with early primary open angle glaucoma(POAG)using a new custom-made pattern,and analyze the characteristics of macular sensitivity.METHODS:This case-control study included 38 patients with POAG,who were divided into pre-perimetric glaucoma(18 eyes of 18 patients),early-stage(20 eyes of 20 patients),and control(20 eyes of 20 patients)groups.All subjects underwent standard 24-2 humphrey visual field test.An MP-3 microperimeter with a new custom-made pattern(28 testing points distributed in four quadrants,covering the central 10°of the retina)was used to evaluate macular sensitivity.Ganglion cell complex(GCC)thicknesses were examined using an RS-3000 Advance OCT system.The features of structure and function were analysed per quadrant.RESULTS:The pre-perimetric glaucoma group had significantly lower inferior hemifield macular sensitivity compared to controls(P<0.05).The early-stage POAG group had significantly lower average,inferior hemifield,inferonasal,and inferotemporal mean sensitivities compared to the pre-perimetric glaucoma group(P<0.05),and lower macular sensitivity in all sectors compared to controls(P<0.05).Regarding GCC thickness,all sectors in the early-stage POAG group became thinner compared to those in controls(P<0.05);whereas all sectors in the early-stage POAG group,except the superonasal quadrant,became thinner compared to those in the pre-perimetric glaucoma group(P<0.05).Macular sensitivity and GCC thickness were significantly associated in each sector.The inferotemporal quadrant had the highest correlation coefficients(0.840).The structure-function relationship for the inferonasal and inferotemporal sectors was stronger compared to the corresponding superior sectors.CONCLUSION:Microperimetry reveals variations in macular sensitivity in patients with early glaucoma earlier than conventional perimetry,particularly in pre-perimetric glaucoma cases in which it might be undetectable by conventional methods.The new custom-made pattern may improve the accuracy of microperimetry by enhancing point arrangement and reducing fatigue effects.Macular sensitivity measured by MP-3 with this pattern shows statistically significant structural and functional associations with the thicknesses of the GCC.

Intraocular pressure and gonioscopic findings in primary angle-closure disease in India—a big data study

AIM:To describe the gonioscopic profile and intraocular pressure(IOP)in primary angle-closure(PAC)disease in patients presenting to a tertiary eye care network in India.METHODS:A cross-sectional hospital-based study that included 31484 new patients presenting between 2011 and 2021.Patients with a clinical diagnosis of PAC/suspect/glaucoma were included.The data was collected from an electronic medical record system.RESULTS:PAC glaucoma(PACG)(47.55%)was the most common diagnosis followed by PAC(39.49%)and PAC suspect(PACS;12.96%).Female preponderance(54.6%)was noted with higher mean age at presentation among males(P<0.0001).PACS and PAC showed the highest prevalence in 6th decade but PACG was higher at 7th decade.The probability of angle opening was 95.93%,90.32%and 63.36%in PACS,PAC and PACG eyes respectively post peripheral iridotomy(PI).Plateau iris syndrome(PIS)was noted in 252 eyes and all showed post dilated rise of IOP.A post dilated IOP rise was also noted with 8.86%,33.95%and 57.19%eyes with PACS,PAC and PACG respectively with IOP rise between 6-8 mm Hg across the disease spectrum.CONCLUSION:The superior quadrant is the narrowest angle and difficult to open with indentation and post PI.The probability of angle opening is less in PIS especially the complete variety along with post dilated IOP rise.The post dilated IOP rise in angle closure eyes warrants a careful dilatation,especially with PIS.

A highly sensitive fluorescent probe RN-NA reveals peroxynitrite as a novel biomarker for primary open angle glaucoma

AIM:To directly quantify peroxynitrite(ONOO-)using a highly sensitive fluorescence resonance energy transfer probe RN-NA,investigate the association between ONOOand primary open angle glaucoma(POAG),and clarify whether RN-NA could be used as a potential tool for POAG diagnosis.METHODS:Plasma and aqueous humor(AH)samples were collected from POAG patients(n=100,age:59.70±6.87y)and age-related cataract(ARC)patients(n=100,age:61.15±4.60y)admitted to our hospital.Next,RN-NA was used to detect ONOO-in plasma and AH samples,and the relationship between ONOO-level and POAG was analyzed using binary logistic regression.Besides,Pearson correlation analysis was applied to characterize the correlation of the levels of ONOO-with the patients’age,intraocular pressure(IOP),and mean deviation of visual field testing.The ONOO-scavenger MnTMPyP was employed to treat the 3-morpholinosyndnomine(SIN-1)-induced ocular hypertension in mice(n=7,6-8wk).Finally,the IOP and ONOO-in both eyes were measured 30min after the last drug treatment.RESULTS:ONOO-levels of AH and plasma were significantly higher in the POAG group than in the ARC group(P<0.01).Additionally,ONOO-levels were closely correlated with POAG in a binary logistic regression analysis[odds ratio(OR)=1.008,95%confidence interval(CI):1.002-1.013,P<0.01 for AH;OR=1.004,95%CI:1.002-1.006,P<0.001 for plasma].Pearson correlation analysis showed that ONOO-levels in AH or plasma were positively associated with visual field defects(R=0.51,P<0.01 for AH;R=0.45,P<0.001 for plasma),and ONOO-levels in plasma and AH were correlated in the POAG group(R=0.69,P<0.001).However,administering MnTMPyP to mouse eyes reversed the elevated IOP caused by SIN-1(P<0.05).CONCLUSION:ONOO-levels in AH and plasma,detected by RN-NA,are significantly related to POAG and positively correlated with visual field defects in POAG patients.Hence,ONOO-is a potential biomarker of POAG,especially advanced POAG.Besides,anti-nitration compounds may be novel ocular hypotensive agents based on the animal study.

Effect of Nozzle Inclination Angle on Fuel-Air Mixing and Combustion in a Heavy Fuel Engine

Heavy-fuel engines are widely used in UAVs(Unmanned Autonomous Vehicles)because of their reliability and high-power density.In this study,a combustion model for an in-cylinder direct injection engine has been imple-mented using the AVL FIRE software.The effects of the angle of nozzle inclination on fuel evaporation,mixture distribution,and combustion in the engine cylinder have been systematically studied at 5500 r/min and consider-ing full load cruise conditions.According to the results,as the angle of nozzle inclination increases,the maximum combustion explosion pressure in the cylinderfirst increases and then it decreases.When the angle of nozzle incli-nation is less than 45°,the quality of the mixture in the cylinder and the combustion performance can be improved by increasing the angle.When the angle of nozzle inclination is greater than 45°,however,the mixture unevenness increases slightly with the angle,leading to a deterioration of the combustion performances.When the angle of nozzle inclination is between 35°and 55°,the overall combustion performance of the engine is rela-tively good.When the angle of nozzle inclination is 45°,the combustion chamber’s geometry and the cylinder’s airflow are well matched with the fuel spray,and the mixture quality is the best.Compared with 25°,the peak heat release rate increases by 20%,and the maximum combustion burst pressure increases by 5.5%.

Gated Neural Network-Based Unsteady Aerodynamic Modeling for Large Angles of Attack

Modeling of unsteady aerodynamic loads at high angles of attack using a small amount of experimental or simulation data to construct predictive models for unknown states can greatly improve the efficiency of aircraft unsteady aerodynamic design and flight dynamics analysis.In this paper,aiming at the problems of poor generalization of traditional aerodynamic models and intelligent models,an intelligent aerodynamic modeling method based on gated neural units is proposed.The time memory characteristics of the gated neural unit is fully utilized,thus the nonlinear flow field characterization ability of the learning and training process is enhanced,and the generalization ability of the whole prediction model is improved.The prediction and verification of the model are carried out under the maneuvering flight condition of NACA0015 airfoil.The results show that the model has good adaptability.In the interpolation prediction,the maximum prediction error of the lift and drag coefficients and the moment coefficient does not exceed 10%,which can basically represent the variation characteristics of the entire flow field.In the construction of extrapolation models,the training model based on the strong nonlinear data has good accuracy for weak nonlinear prediction.Furthermore,the error is larger,even exceeding 20%,which indicates that the extrapolation and generalization capabilities need to be further optimized by integrating physical models.Compared with the conventional state space equation model,the proposed method can improve the extrapolation accuracy and efficiency by 78%and 60%,respectively,which demonstrates the applied potential of this method in aerodynamic modeling.