Optimal Angle Research Articles

Optimal impact angle guidance law with barrier constraint

This paper presents an optimal guidance law for missile to achieve desired impact angles on a stationary target while accommodating the barrier constraint. The proposed guidance law consists of two parts: a baseline guidance command for intercepting the target with desired impact angles, and a bias command to prevent collision with the barrier. Specifically, the baseline guidance command is derived by solving a linearized optimal control problem, and its explicit trajectory solution is also obtained for collision estimation. The bias command is designed using a novel guidance error that is defined based on the geometrical relationship between the barrier and the proposed explicit trajectory solution. The new guidance law can be easily implemented to a variety of practical engagement geometries, resulting in successful collision avoidance and minimal control efforts. Its effectiveness and robustness are demonstrated via extensive numerical simulations.

Modelling Wear Phenomena Specific to Mixer Blades in Concrete Production Plants

In the cement concrete manufacturing industry, mixers are critical pieces of equipment that play an essential role. Mixers ensure, by mechanically mixing the materials that make up the concrete, the homogeneity of the mixture. Since the active elements of the mixer in the concrete industry—the mixing blades—come into permanent contact with the mineral aggregates in the mixture formed by water and cement, they are permanently subjected to a strong abrasive–erosive wear process. The authors of this article were concerned with the establishment of tribological models for studying the wear of mixing blades, in order to identify the influence of their constructive parameters on the wear intensity. A complex model (Kraghelsky–Nepomnyashchi model) was adopted for the study. The modeling results revealed that the wear intensity decreases with an increasing blade angle of attack and increases linearly with increasing speed, as well as with an increasing friction coefficient. The modeling results confirm that the wear intensity is lowest when the mixing blade is inclined at a 60° angle, while the highest value is recorded for 30°. By identifying the angle at which the greatest wear of blades occurs, interventions can be made in the design of a more durable mixer (with the optimal installation angle of the mixer blades), thus requiring fewer corrective maintenance interventions. Based on these findings, we conclude that the complex model used in the experiment can provide a convenient and efficient tool for the study of erosive–abrasive phenomena.

A multiobjective beam angle optimization framework for intensity-modulated radiation therapy

Radiation therapy treatment planning is inherently a multiobjective problem, aiming to obtain the best tradeoffs between irradiating the tumor with the prescribed dose and sparing as much as possible the surrounding healthy organs. Many different multiobjective approaches have been proposed for the optimization of radiation intensities for fixed beam irradiation directions. However, multiobjective beam angle optimization is seldom considered. The purpose of this paper is to introduce a new multiobjective optimization framework that explicitly and simultaneously considers the optimization of intensities and also beam directions. Whilst multiobjective optimization of radiation intensities considering a fixed set of beam directions gives rise to a single Pareto front, beam angle optimization gives rise to the appearance of multiple Pareto fronts, each one associated with a given beam angle set. Our framework proposes a beam angle set choice based on the evaluation of non-dominated solutions belonging to different Pareto fronts, using a tree-based approach and a performance indicator to assess the quality of each Pareto front. The proposed approach, illustrated by head-and-neck cancer cases, allows for more flexibility in the calculation of solutions and a better understanding of the existing compromises between different objectives.

Study on the effect of PV tilt angle on power generation

The power generation of a photovoltaic (PV) system is significantly influenced by the tilt angle of the module. The system achieves the highest power efficiency when operated at the optimal tilt angle, which is typically considered in the design of system installation. In this study, the optimal tilt angle of photovoltaic (PV) modules is determined by using PVsyst software and analyzed through shadow simulation under specific boundary conditions. The study examines the power generation of photovoltaic (PV) panels at various inclination angles and illustrates the impact of inclination angle on PV panel power generation by using project-specific data. The study results indicate that the secondary optimization of the tilt angle by PVsyst, in conjunction with the geographic factors of a specific region in Hainan, reveals that the optimal installation tilt angle for maximum power generation benefit is 9°. This finding aligns with the best power generation and benefits from the actual installation, which is at 10° (adjacent to 9°). The conclusions drawn from the exploration emphasize the essential nature of EPC optimization for future projects, as it can serve as a valuable reference for the design of photovoltaic power generation systems.

Modified silica nanoparticles stabilized foam for enhanced oil recovery

Foam has been successfully used to improve mobility control in the process of enhanced oil recovery, yet the instability of foam limits its application. Modified nanoparticles with varying wettability were prepared by reacting 3-methacryloxypropyltrimethoxysilane (KH570) with spherical SiO2 nanoparticles in this study. Fourier transform infrared (FTIR) spectra and the measured contact angles were used to characterize the surface properties of the modified SiO2 particles, and the foam stabilization effects of wettability SiO2 were compared. Pore-scale visualization experiments were conducted using a 2D micromodel to identify the prevailing enhanced oil recovery (EOR) mechanisms of modified nano SiO2-Sodium alpha-olefin Sulfonate (AOS) foam flooding. The results indicate that modified SiO2 effectively improves foam stability by adsorbing on the bubble surface and forming a mesh-like structure. The optimum contact angle of the particles is approximately 60°, resulting in a significant increase in drainage half-life by 29.4% compared to foam stabilized only by AOS. Additionally, Foam stabilized by modified SiO2 demonstrates superior dynamic stability and deformation resistance. The modified SiO2 stabilized foam exhibits enhanced interfacial viscoelasticity and plugging and profile control performance, surpassing AOS foam in displacing more residual oil in dead-end pores. The oil recovery of the micro model was determined by ImageJ software. KH570@SiO2 (0.2wt%)-AOS (0.2wt%) foam flooding increased the recovery by 8.7% compared to AOS (0.2wt%) foam flooding.

A critical eye on metopic craniosynostosis: A retrospective study assessing orbital dysmorphology as a marker of disease

This investigation sought to ascertain whether orbital morphology could predict genuine metopic craniosynostosis (MCS).The study retrospectively analyzed preoperative three-dimensional computed tomography (3D-CT) scans of patients who underwent surgical correction for MCS. MCS severity was evaluated using the interfrontal angle (IFA). Orbital dysmorphology was assessed based on multiple angles, including supraorbital notches and nasion (SNS), infraorbital foramina and nasion (INI), zygomaticofrontal suture-supraorbital notch-dacryon (ZSD), and orbital long axis (OLA). Results were juxtaposed against age/gender-matched controls and individuals with non-synostotic metopic ridge (MR).The study included 177 patients: 68 MCS, 35 MR, and 74 control subjects. All orbital measurements exhibited significant differences across groups. IFA demonstrated a strong association with all orbital measurements, particularly SNS (B = 0.79, p < 0.001). SNS showed the highest area under the curve among orbital measurements (0.89). Using a 95% sensitivity threshold, the optimal diagnostic angle for SNS was 129.23° (specificity 54%, sensitivity 96%).These findings suggest a correlation between orbital dysmorphology and trigonocephaly severity. The observed dysmorphology manifested in a superomedially accentuated rotational pattern. Importantly, SNS angle predicted MCS, with an angle greater than 130° indicating <5% likelihood of MCS diagnosis. The simplicity of measuring SNS angle on any 3D-CT scan highlights its practical use for assisting with MCS diagnosis.

Study of backflow volume due to check valve’s lag motion in liquid hydrogen piston pump

The liquid hydrogen piston pump is the key equipment in the process of storage, transportation, and refueling of liquid hydrogen. The timely motions of suction and discharge valves are beneficial to the transport performance and volumetric efficiency of the pump. This study sets up an operation frame of the liquid hydrogen piston pump in which reciprocating pistons and check valves with a conical spool interact. Backflow occurs when there is a delay in the spool’s motion, which is more common in suction valves than in discharge valves. The influence of spring stiffness and spool-head angle of the valve cone on the suction valve’s backflow volume is analyzed and further optimized. The results indicate that there exists an optimal spool-head angle and spring stiffness for minimizing backflow volume during the closing phase of the suction valve. This research contributes to enhancing the volumetric efficiency of the liquid hydrogen piston pump.

Influence of Different Wingtip Devices on Aerodynamic Characteristics of UAV

The wingtip device plays an important role in increasing the range of UAVs because the winglets can effectively reduce the induced drag. The purpose of this paper is to explore the influence of wingtip device parameters on the lift-to-drag ratio of UAVs. Using the Fluent analysis system, the drag reduction performance of the winglet-winglet structure based on a UAV was analyzed at different angles of attack. Firstly, from the perspective of aerodynamic performance, the optimal cant and sweep angles of the blended winglets were selected by simulations. Then, the best-blended winglet and the blended split were simulated and analyzed, and the difference between the two on the lift-to-drag ratio and the flow field around the wing were compared. Compared with the traditional wind tunnel test, the CFD technology used greatly shortens the research cost and experimental cycle and provides help for the design of the UAV wingtip work.

Lightweight concrete with low-carbon artificial aggregates recycled from biomass ash and slurry waste

The development of artificial aggregates (AAs) significantly reduces carbon emissions of concrete production since the aggregates account for about 70% volume of all concrete ingredients. Therefore, a type of low-carbon AAs was prepared with full solid wastes of biomass ash (BA) and slurry waste (SW) through a pelletizing technique and carbonation curing methods. This study focused on evaluating the feasibility of AAs produced by the synergistic effect of BA and SW; identifying and optimizing the pelletization parameters through the response surface methodology (RSM) with experimental tests; analyzing the effects of blending amounts of BA on the properties of AAs; discussing the improvement of carbonation curing methods for AAs production; assessing the properties of the prepared lightweight concrete (LWC) with AAs. The results indicate the addition of 20 wt% BA lightened the bulk density of AAs by about 13% but weakened strength by nearly half due to its porous characteristics. The appropriate incorporation of 5 wt% BA could improve the individual pellet and cylinder compressive strength by about 2% and 16%, respectively. AAs cured in pressurized carbonation of 3 d and wet carbonation of 10 min demonstrated similar enhancement effects. Pressurized and wet carbonation curing showed respective superiorities in terms of improving effect and curing efficiency. The effects of inclination angle and moisture content on the average particle size are more significant than those of rotation speed, while rotational speed has a dominant effect on the bulk density. RSM simulations identified the optimal inclination angle, rotation speed, and moisture content as 45°, 38.5 r/min, and 37.5%, respectively. The LC40 high-strength LWC can be prepared by using full substitution pre-wetting AAs.

Air tightness detection method in parallel for aerospace: mechanical design, system modeling and optimum control

To address the problems of high cost, complex operation, and low efficiency of existing equipment for aerospace, a simple but efficient multichannel air tightness detection device is designed. A physical system model is constructed for the process of inflation, deflation, and inflation with leakage. The expression between the inflation/deflation rate and the valve area is obtained. Through modeling the intersection and rotation of spatial curves, the relationship between the valve area and the valve core angle is derived, and the optimal valve core angle calculation method is proposed to achieve precise rate control of inflation and deflation. Simulation experiments and numerical analysis demonstrate the superiority of the proposed system scheme, the effectiveness of the control method, as well as the accuracy of the mathematical model. For the tested object of 0.3 L, the target pressure of 400 KPa, and the inflation and deflation rate of 75 Kpa/min, by using four channels with a 10 s interval for sequential operation and adjusting valves every 60 s, the efficiency of inflation and deflation is more than 3.5 times that of a single device with a single circuit. Its performance is not much different from real-time automatic control equipment, but the economy is greatly improved.

1521: evaluation of an angle optimization algorithm for radiotherapy treatment planning in lung cancer

1521: evaluation of an angle optimization algorithm for radiotherapy treatment planning in lung cancer

Comprehensive Performance Improvement of SRG by Turn-ON Angle Optimization Using Linear Normalized Model

Comprehensive Performance Improvement of SRG by Turn-ON Angle Optimization Using Linear Normalized Model

Optimizing Solar Heating for Thangka Exhibition Halls: A Case Study in Malkang Cultural Village

With the continuous development of rural revitalization and urbanization in China, the sustainable transformation of traditional rural architecture has become increasingly important. This study takes the Thangka exhibition hall in rural Malkang, Sichuan Province, as the research object and proposes a Thangka exhibition hall architectural design centered around solar heating and aiming for near-zero energy consumption. The research method involves establishing a solar energy system model on the roof of the exhibition hall and utilizing solar angle and area calculation formulas along with simulation software to calculate the optimal installation angle and area of solar panels, with the aim of achieving indoor temperatures that meet Thangka protection requirements while achieving zero-energy heating. Preliminary results indicate that this solar-centric near-zero energy architectural design can effectively promote the increase in indoor temperature through solar thermal conversion. Additionally, through calculation and simulation, the optimal installation angle for the solar panels achieving zero-energy heating is determined to be 24.25 with an azimuth angle of −1.2. The optimum installation area for solar panels is 8.2 square meters in the showroom and 2.7 square meters in the storeroom. Among these, the solar panel area for the Thangka exhibition hall constitutes 4.12% of the total area and is required for maintaining Thangka protection temperature requirements throughout the year, while the solar panel area for the storage room constitutes 1.88% and is also needed for the same purpose. Studying the optimal installation angle and area of solar panels can transform the exhibition hall into a near-zero-energy building, meeting the temperature requirements for Thangka preservation and human thermal comfort, while also achieving optimal economic benefits. This provides guidance and a reference for promoting near-zero-energy buildings in rural areas.

An Analysis of the Kinematics and Dynamics Performance of a New Type of Three-Pronged Sliding Universal Coupling

The three-pronged sliding universal coupling is a new kind of three-pronged coupling. The purpose of this study is to demonstrate that, compared with a traditional unequal angular velocity universal coupling (such as the Hooke universal coupling), the universal coupling has the superior characteristics of constant angular speed transmission, simple structure and strong transmission capacity by performing kinematic and dynamic analysis of the new three-pronged sliding constant angular velocity universal coupling. It provides a broad prospect for applications in automotive and other fields. To study its kinematic and dynamic characteristics, directional cosine matrices are utilized as tools to analyze the coordinate systems by establishing simplified geometric models and corresponding motions. Through the analysis of the motions of the input and output shafts and employing the method of single-force element, a set of equilibrium equations for the forces acting on the output shaft and the input shaft are formulated for solution analysis. The research indicates that during the rotation process, there exists a small angular difference between the input shaft and the intermediate shaft, demonstrating the quasi-constant angular velocity characteristics of the new tripod sliding universal coupling. The curves of the forces and force moment acting on each component of the coupling approximate sinusoidal curves. The optimal operating angle range for the new tripod universal coupling is at angle , during which the system exhibits good transmission and mechanical performance. It can be widely used in the automobile industry, tie steel industry and other occasions that require angular transmission. It is especially used in high-speed operation and large transmission capacity.

Modeling effects of swirl burners on the heating quality of slabs and flame morphology in a walking-beam reheating furnace

This paper developed a model of zone segment swirl burners to realize individual separation of swirl burners within a CFD model of an industrial-scale walking-beam reheating furnace. Numerical results are validated against the experimental measurements, demonstrating good agreement and credibility. Leveraging this model, a comprehensive investigation on the effect of swirl angle on the flame morphology and the slab heating quality has been conducted. Comparing various swirl angles (0°, 25°, 45°, and 65°) provides valuable insights into their impact on flame morphology, and slab heating quality. A swirl angle of 25° has been identified as optimal, yielding the maximum flame area within the furnace, measuring 326.09 m2. Furthermore, it reduces the maximum absolute temperature deviation of the discharged slab’s top surface centerline to 7.64 K, marking a substantial 25.83 % reduction compared to the 0° angle. These results highlight the critical role swirl burners play in the reheating furnace and identify the optimal swirl angle for effectively enhancing both the economic benefits and product quality in industrial processes.

Experimental Investigation of the Influence of Longitudinal Tilt Angles on the Thermal Performance of a Small-Scale Linear Fresnel Reflector

This paper analyses the influence of the longitudinal tilt angle of the secondary system of a low-concentration photovoltaic system based on a small-scale linear Fresnel reflector. Several evaluation indicators, such as useful heat gain, thermal efficiency, incident solar irradiance gain on the photovoltaic cells, and total useful energy gain, were evaluated for five wind speed conditions and six locations in the Northern Hemisphere. The tests were performed with two small-scale linear Fresnel reflector configurations: the classical large-scale linear Fresnel reflector configuration (base configuration) and the optimal longitudinal tilt angle configuration (longitudinal tilt configuration). An experimental platform based on an open-loop wind tunnel was designed and built for this purpose. As far as useful heat production, the longitudinal tilt configuration performs worse as the longitudinal tilt angle and wind speed increase. A useful heat gain 33.91% lower than the base configuration is obtained with a wind speed of 10.03 (m/s) at the 36.86 (°) latitude location. Thermal efficiency decreases with increasing wind speed and longitudinal tilt angle. The thermal efficiency is between 0.3 and 0.2 with wind speeds of 4.99 (m/s) and 10.03 (m/s). The longitudinal tilt configuration shows the best increase in total useful energy gain in the absence of wind (up to 53% at a latitude of 36.86 (°)). This increase is 25% at this same location with a wind speed of 10.03 (m/s). It can be concluded that the effect of the longitudinal tilt of the secondary system has a positive effect. To highlight the importance of this work, the results obtained in the configuration comparison were used to compare a nonconcentrating photovoltaic system and a low-concentration photovoltaic system. The incident solar irradiance on the photovoltaic cells is much higher with nonconcentrating photovoltaic technology. This solar irradiance gain is over 60% for the base configuration and 45% for the longitudinal tilt configuration. The total useful energy gain is 70% in the absence of wind and at the 36.86 (°) latitude location in favour of the low-concentration photovoltaic system. The nonconcentrating photovoltaic system performs better with a wind speed of 10.03 (m/s).

Enhancing acoustic levitation capacity through array geometry optimization

The contactless micromanipulation capability and microgravity environment provided by the acoustic levitation technology have excellent application prospects in many fields, such as droplet dynamics, solidification state physics, life sciences, etc. However, the applications are severely constrained by the limitation of the transducer power. In this paper, we explore an array geometry optimization framework to improve the levitation capability. First, the acoustic pressure attenuation and directional characteristics of commercial transducers are analyzed to uncover the mechanism of the array geometry affecting the acoustic radiation force (ARF). Second, based on the Gor'kov potential theory, the array geometry form of N-elements is derived, and the arrangement in the spherical ring (ASR) method is proposed to obtain the element coordinates. Then, spherical radius and array height are adjusted to obtain the optimal array geometry. On this basis, the directional angle of each transducer is further optimized. Finally, simulation and physical verification are carried out. The simulation results indicate that the ARF increases and then decreases with the spherical radius and array height, which are the existing maximum values. Directional angle optimization (DAO) can improve the ARF, particularly when the array height exceeds the sphere diameter. These findings are consistent with the analytical results. Notably, we built a prototype physical system, and the physical experiments showed that the optimized array improved the axial ARF by 201.2% and the radial ARF by 115.9% over the conventional array. The works presented in this paper offer a valuable design approach for acoustic levitation arrays, thereby contributing to the advancement and application of ultrasonic array levitation technology.

3D printed temporal bones for preoperative simulation and planning

ObjectiveDemonstrate the utility of 3D printed temporal bone models in individual patient preoperative planning and simulation. Methods3D models of the temporal bone were made from 5 pediatric and adult patients at a tertiary academic hospital with challenging surgical anatomy planned for cochlear implantation or exteriorization of cholesteatoma with complex labyrinthine fistula. The 3D models were created from CT scan used for preoperative planning, simulation and intraoperative reference. The utility of models was assessed for ease of segmentation and production and impact on surgery in regard to reducing intraoperative time and costs, improving safety and efficacy. ResultsThree patients received cochlear implants, two exteriorization of advanced cholesteatoma with fistulas (1 internal auditory canal/cochlea, 1 all three semicircular canals). Surgical planning and intraoperative referencing to the simulations by the attending surgeon and trainees significantly altered original surgical plans. In a case of X-linked hereditary deafness, optimal angles and rotation maneuvers for cochlear implant insertion reduced operating time by 93 min compared to the previous contralateral side surgery. Two cochlear implant cases planned for subtotal petrosectomy approach due to aberrant anatomy were successfully approached through routine mastoidectomy. The cholesteatoma cases were successfully exteriorized without necessitating partial labyrinthectomy or labyrinthine injury. There were no complications. Conclusion3D printed models for simulation training, surgical planning and use intraoperatively in temporal bone surgery demonstrated significant benefits in designing approaches, development of patient-specific techniques, avoidance of potential or actual complications encountered in previous or current surgery, and reduced surgical time and costs.

Measurement technology based on a Stokes parametric polarization system

Structured light measurement systems often use polarization filters to reduce image interference from highly reflective areas. This method can be effective, but it may also reduce the brightness of specific areas, particularly overly dark portions, which can affect the accuracy of the measurement results. This paper proposes a measurement method for a polarization system based on Stokes parameters to solve the problem. After adjusting the polarization filter to angles of 0°, 45°, and 90°, the camera captures an image of the object and calculates the corresponding Stokes parameters to generate the expected polarization angle histogram. Then, based on the detailed information on the angle distribution, the accurate mathematical model is used to screen the interval, and the optimal polarization angle is determined by orthogonal processing while ensuring the signal-to-noise ratio and image quality. Finally, an image fusion technology synthesizes a set of fringe projection images with the preferred polarization angles. Experiments have shown that this new method effectively addresses the issue of interference in the highlighted region when using conventional polarization filters. Additionally, it significantly improves the quality of the fringe pattern. The polarization angle selection in the experimental process is made more rapid and accurate through the quantitative mathematical model calculation of the polarization angle, significantly improving the system’s measurement efficiency.

SLOPE ANALYSIS OF CLOT-ADJUSTED SSI-FY4A DATA FOR SOLAR PV POWER POTENTIAL ASSESSMENT IN THE PHILIPPINES

Abstract. Utilization rate of energy from solar photovoltaic (PV) systems has surged considerably with the increase in global demand for sustainable energy solutions.The angle at which panels are positioned relative to the horizontal plane must be aligned with the sun's incoming radiation to achieve optimum power production. Unfortunately, this ideal alignment is not always feasible, particularly for panels lacking tracking systems. Therefore, determining the best tilt angle becomes a key factor that significantly influences the effectiveness of solar PV systems, considering various influencing factors. The study aims to establish the relationship between different slopes and solar PV performance and to assess the impact of this on energy generation efficiency for specific locations across Luzon and Mindanao. The study focuses on determining the optimal tilt for specific locations across Luzon, Visayas, and Mindanao. Sites including Metro Manila, Cebu, and Davao were selected as representative areas for each respective island group for being the most populous cities in their respective geographical island groups. Theoretical solar energy obtained from SSI was CLOT-adjusted and incorporated with dust and temperature effects to determine the maximum solar energy resource potential within the study area. Results show that the highest solar PV potential was determined at 5°–10° tilt angle for both Metro Manila and Davao followed by 10–20° and 20–30° tilt angle with an average of 86.42 W solar PV potential (PPV). For Cebu, the highest solar PV potential was determined at 20° to 30° tilt angle with the value of 95.99 W solar PV potential (PPV). The lowest PPV was found on installations with tilt &gt; 30° in all the study areas at an average of 65.02 W. This suggests that to maximize solar PV output in different regions, installations should be tilted according to the optimal tilt angle specific to that region. The latitude differences across the country significantly impact which tilt angle is most effective, as they influence the amount of sunlight received in each area. To improve the accuracy of future studies, it is recommended to increase the number of data points per slope interval. While the differences observed in this study were small, having more data points can enhance the precision of average values obtained from formulas.