Joint Research on Aerodynamic Characteristics and Handling Stability of Racing Car under Different Body Attitudes

Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 393
Author(s):  
Zhe Zhang ◽  
Qiang Wang ◽  
Shida Song ◽  
Chengchun Zhang ◽  
Luquan Ren ◽  
...  

With the rapid development of FSAE, the speed of racing cars has increased year by year. As the main research content of racing cars, aerodynamics has received extensive attention from foreign teams. For racing cars, the aerodynamic force on the aerodynamic device ultimately acts on the tires through the transmission of the body and the suspension. When the wheel is subjected to the vertical load generated by the aerodynamic device, the ultimate adhesion capacity of the wheel is improved. Under changing conditions, racing wheels can withstand greater lateral and tangential forces. Therefore, the effects of aerodynamics have a more significant impact on handling stability. The FSAE racing car of Jilin University was taken as the research object, and this paper combines the wind tunnel test, the numerical simulation and the dynamics simulation of the racing system. The closed-loop design process of the aerodynamics of the FSAE racing car was established, and the joint study of aerodynamic characteristics and handling stability of racing car under different body attitudes was realized. Meanwhile, the FSAE car was made the modification of aerodynamic parameter on the basis of handling stability. The results show that, after the modification of the aerodynamic parameters, the critical speed of the car when cornering is increased, the maneuverability of the car is improved, the horoscope test time is reduced by 0.525 s, the downforce of the car is increased by 11.39%, the drag is reduced by 2.85% and the lift-to-drag ratio is increased by 14.70%. Moreover, the pitching moment is reduced by 82.34%, and the aerodynamic characteristics and aerodynamic efficiency of the racing car are obviously improved. On the basis of not changing the shape of the body and the aerodynamic kit, the car is put forward to shorten the running time of the car and improve the comprehensive performance of the car, so as to improve the performance of the car in the race.

Author(s):  
Konstantin I. Matveev ◽  
Miles P. Wheeler

Abstract An innovative unmanned aerial vehicle with a tubular body and a vectored thruster is considered in this study. In order to optimize the vehicle design and develop effective means for its control, aerodynamic characteristics of this vehicle need to be known. Computational fluid dynamics studies employing STAR-CCM+ software have been carried out for this UAV in near-hovering regimes. Aerodynamic simulations employed the SST k–ω turbulence model, γ transition model, and a virtual actuator disk model. After conducting a validation study with a cylinder in axial flow, modeling of the UAV setup was completed for a range of propulsor orientations and cross winds. The aerodynamic phenomena are found to become more complex with increasing the propulsor angle with respect to the main body axis and in stronger cross winds due to interactions between the incident flow, the propulsor jet, and the body surface. At the propulsor deflection angle of 15°, the horizontal aerodynamic force on the body was augmented by 0.02–0.07 of the propulsor thrust magnitude in various wind conditions, whereas the axial downward force increased by 0.01–0.03 of the thrust. In cross winds with the relative velocity magnitude of 0.65, the horizontal aerodynamic force on the body increased by about 0.25 of the propulsor thrust magnitude, while the axial downward force increased by about 0.05 of the thrust.


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Ying Wu ◽  
Jikun Liu

AbstractWith the rapid development of gymnastics technology, novel movements are also emerging. Due to the emergence of various complicated new movements, higher requirements are put forward for college gymnastics teaching. Therefore, it is necessary to combine the multimedia simulation technology to construct the human body rigid model and combine the image texture features to display the simulation image in texture form. In the study, GeBOD morphological database modeling was used to provide the data needed for the modeling of the whole-body human body of the joint and used for dynamics simulation. Simultaneously, in order to analyze and summarize the technical essentials of the innovative action, this experiment compared and analyzed the hem stage of the cross-headstand movement of the subject and the hem stage of the 180° movement. Research shows that the method proposed in this paper has certain practical effects.


2021 ◽  
Vol 7 (1) ◽  
pp. 540-555
Author(s):  
Hayley L. Mickleburgh ◽  
Liv Nilsson Stutz ◽  
Harry Fokkens

Abstract The reconstruction of past mortuary rituals and practices increasingly incorporates analysis of the taphonomic history of the grave and buried body, using the framework provided by archaeothanatology. Archaeothanatological analysis relies on interpretation of the three-dimensional (3D) relationship of bones within the grave and traditionally depends on elaborate written descriptions and two-dimensional (2D) images of the remains during excavation to capture this spatial information. With the rapid development of inexpensive 3D tools, digital replicas (3D models) are now commonly available to preserve 3D information on human burials during excavation. A procedure developed using a test case to enhance archaeothanatological analysis and improve post-excavation analysis of human burials is described. Beyond preservation of static spatial information, 3D visualization techniques can be used in archaeothanatology to reconstruct the spatial displacement of bones over time, from deposition of the body to excavation of the skeletonized remains. The purpose of the procedure is to produce 3D simulations to visualize and test archaeothanatological hypotheses, thereby augmenting traditional archaeothanatological analysis. We illustrate our approach with the reconstruction of mortuary practices and burial taphonomy of a Bell Beaker burial from the site of Oostwoud-Tuithoorn, West-Frisia, the Netherlands. This case study was selected as the test case because of its relatively complete context information. The test case shows the potential for application of the procedure to older 2D field documentation, even when the amount and detail of documentation is less than ideal.


2012 ◽  
Vol 182-183 ◽  
pp. 1630-1633
Author(s):  
Hao Jun Hu ◽  
Yuan Han Wang ◽  
Zi Dong Hu

Based on the second development at the ANSYS computing platform, finite element model of a Tower-Line Coupling system was established. The computational fluid dynamics module (CFX) was used for the numerical simulation of the aerodynamic characteristics of iced conductor. On the basis of the Kaimal spectrum, fast Fourier transform was introduced to prepare the wind speed simulation program WVFS with spatial correlation into consideration, thus generating aerodynamic coefficients of iced conductor at different wind attack angles as well as wind speed time series at tower-line nodes. According to the finite element model of continuous multi-conductors and the aerodynamic force- wind attack angle curve, the explicit integration is applied for numerical solution of galloping of iced conductor.


Robotica ◽  
2010 ◽  
Vol 29 (5) ◽  
pp. 733-743 ◽  
Author(s):  
Conghui Liang ◽  
Hao Gu ◽  
Marco Ceccarelli ◽  
Giuseppe Carbone

SUMMARYA mechanical design and dynamics walking simulation of a novel tripod walking robot are presented in this paper. The tripod walking robot consists of three 1-degree-of-freedom (DOF) Chebyshev–Pantograph leg mechanisms with linkage architecture. A balancing mechanism is mounted on the body of the tripod walking robot to adjust its center of gravity (COG) during walking for balancing purpose. A statically stable tripod walking gait is performed by synchronizing the motions of the three leg mechanisms and the balancing mechanism. A three-dimensional model has been elaborated in SolidWorks® engineering software environment for a characterization of a feasible mechanical design. Dynamics simulation has been carried out in the MSC.ADAMS® environment with the aim to characterize and to evaluate the dynamic walking performances of the proposed design with low-cost easy-operation features. Simulation results show that the proposed tripod walking robot with proper input torques, gives limited reaction forces at the linkage joints, and a practical feasible walking ability on a flatten ground.


2021 ◽  
pp. 8-14
Author(s):  
Светлана Тарасовна Быкова ◽  
Тамара Григорьевна Калинина ◽  
Ирина Макаровна Московская

Полноценное, сбалансированное питание - основной фактор в формировании здоровья детей, когда в организме наиболее интенсивно протекают процессы роста и развития, формируются и созревают многие органы и системы, совершенствуются их функции. В статье приведены основные направления исследований зарубежных и отечественных ученых по лечению генетических заболеваний, таких как фенилкетонурия. Одним из приоритетных направлений в области здорового питания населения России в соответствии со Стратегией научно-технологического развития РФ до 2030 г. является развитие производства пищевых продуктов, обогащенных незаменимыми ингредиентами, специализированных продуктов детского питания, продуктов функционального назначения, диетических пищевых продуктов и биологически активных добавок. По данным ВОЗ от структуры питания на 70 % зависят здоровье и физическое развитие детей и подростков. Фенилкетонурия (ФКУ) - наследственное заболевание, вызывающее нарушение метаболизма аминокислоты фенилаланина у ребенка, одно из первых, рекомендованных ВОЗ для ранней диагностики у новорожденных. Отсутствие лечения вызывают серьезное поражение центральной нервной системы, отставание в умственном и физическом развитии. Особенностью современного этапа развития диетотерапии для детей, страдающих различными заболеваниями, в том числе наследственными, является разработка качественных функциональных продуктов питания, способствующих сохранению и улучшению здоровья ребенка за счет регулирующего и нормализующего воздействия на организм с учетом его физиологического состояния и возраста. Данные продукты можно широко использовать в практике лечебного питания не только в составе гипофенилаланиновой диеты, но и при любых заболеваниях, требующих ее соблюдения. В настоящее время единственным методом лечения ФКУ является диетотерапия, организованная с первых дней жизни с использованием специализированных смесей без фенилаланина. Из питания исключаются высокобелковые продукты растительного и животного происхождения. Целью лечебного воздействия диеты на ребенка является поддержка концентрации фенилаланина (ФА) в крови в пределах 2-12 мг на 100 мл в зависимости от возраста ребенка. Full-fledged balanced nutrition is the main factor in the formation of children's health, when the processes of growth and development are most intense in the body, many organs and systems are formed and mature, and their functions are improved. The article presents the main research areas of foreign and domestic scientists on the treatment of genetic diseases, such as phenylketonuria. One of the priority areas in the field of healthy nutrition of the Russian population in accordance with the Strategy for Scientific and Technological Development of the Russian Federation until 2030 is the development of the production of food products enriched with essential ingredients, specialized children's food products, functional products, dietary food products and biologically active additives. According to WHO, the health and physical development of children and adolescents depends on the nutritional structure by 70%. Phenylketonuria (PKN) - an inherited disease that causes impaired metabolism of the amino acid phenylalanine in a child - is one of the first recommended by WHO for early diagnosis in newborns. Lack of treatment causes serious damage to the central nervous system, a lag in mental and physical development. A feature of the modern stage of development of dietary therapy for children suffering from various diseases, including hereditary ones, is the development of quality functional food products that contribute to the preservation and improvement of the health of the child, due to the regulatory and normalizing effect on the body, taking into account its physiological state and age. These products can be widely used in the practice of therapeutic nutrition not only in the sastava of the hypophenylalanine diet, but also for any diseases requiring its observance. Currently, the only method of treating PKN is diet therapy, organized from the first days of life using specialized mixtures without phenylalanine. High-protein products of vegetable and animal origin are excluded from nutrition. The goal of the therapeutic effect of the diet on the child is to maintain the concentration of phenylalanine (FA) in the blood in the range of 2-12 mg per 100 ml, depending on the age of the child.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yusheng Lu ◽  
Jiantong Zhang

PurposeThe digital revolution and the use of big data (BD) in particular has important applications in the construction industry. In construction, massive amounts of heterogeneous data need to be analyzed to improve onsite efficiency. This article presents a systematic review and identifies future research directions, presenting valuable conclusions derived from rigorous bibliometric tools. The results of this study may provide guidelines for construction engineering and global policymaking to change the current low-efficiency of construction sites.Design/methodology/approachThis study identifies research trends from 1,253 peer-reviewed papers, using general statistics, keyword co-occurrence analysis, critical review, and qualitative-bibliometric techniques in two rounds of search.FindingsThe number of studies in this area rapidly increased from 2012 to 2020. A significant number of publications originated in the UK, China, the US, and Australia, and the smallest number from one of these countries is more than twice the largest number in the remaining countries. Keyword co-occurrence is divided into three clusters: BD application scenarios, emerging technology in BD, and BD management. Currently developing approaches in BD analytics include machine learning, data mining, and heuristic-optimization algorithms such as graph convolutional, recurrent neural networks and natural language processes (NLP). Studies have focused on safety management, energy reduction, and cost prediction. Blockchain integrated with BD is a promising means of managing construction contracts.Research limitations/implicationsThe study of BD is in a stage of rapid development, and this bibliometric analysis is only a part of the necessary practical analysis.Practical implicationsNational policies, temporal and spatial distribution, BD flow are interpreted, and the results of this may provide guidelines for policymakers. Overall, this work may develop the body of knowledge, producing a reference point and identifying future development.Originality/valueTo our knowledge, this is the first bibliometric review of BD in the construction industry. This study can also benefit construction practitioners by providing them a focused perspective of BD for emerging practices in the construction industry.


2021 ◽  
Author(s):  
Jiuliang Gan ◽  
Toshinori Watanabe ◽  
Takehiro Himeno

Abstract The unsteady behavior of the shock wave was studied in an oscillating transonic compressor cascade. The experimental measurement and corresponding numerical simulation were conducted on the cascade with different shock patterns based on influence coefficient method. The unsteady pressure distribution on blade surface was measured with fast-response pressure-sensitive paint (PSP) to capture the unsteady aerodynamic force as well as the shock wave movement. It was found that the movement of shock waves in the neighboring flow passages of the oscillating blade was almost anti-phase between the two shock patterns, namely, the double shocks pattern and the merged shock pattern. It was also found that the amplitude of the unsteady pressure caused by the passage shock wave was very large under the merged shock pattern compared with the double shocks pattern. The stability of blade vibration was also analyzed for both shock patterns including 3-D flow effect. These findings were thought to shed light on the fundamental understanding of the unsteady aerodynamic characteristics of oscillating cascade caused by the shock wave behavior.


Author(s):  
Yunpeng Wang ◽  
Zonglin Jiang ◽  
Honghui Teng

Shock tunnels create very high temperature and pressure in the nozzle plenum and flight velocities up to Mach 20 can be simulated for aerodynamic testing of chemically reacting flows. However, this application is limited due to milliseconds of its test duration (generally 500 μs–20 ms). For the force test in the conventional hypersonic shock tunnel, because of the instantaneous flowfield and the short test time [1–4], the mechanical vibration of the model-balance-support (MBS) system occurs and cannot be damped during a shock tunnel run. The inertial forces lead to low frequency vibrations of the model and its motion cannot be addressed through digital filtering. This implies restriction on the model’s size and mass as its natural frequencies are inversely proportional the length scale of the model. As to the MBS system, sometimes, the lowest natural frequency of 1 kHz is required for the test time of typically 5 ms in order to get better measurement results [2]. The higher the natural frequencies, the better the justification for the neglected acceleration compensation. However, that is very harsh conditions to design a high-stiffness MBS structure, particularly a drag balance. Therefore, it is very hard to carried out the aerodynamic force test using traditional wind tunnel balances in the shock tunnel, though its test flow state with the high-enthalpy is closer to the real flight condition.


Author(s):  
Dilong Guo ◽  
Wen Liu ◽  
Junhao Song ◽  
Ye Zhang ◽  
Guowei Yang

The aerodynamic force acting on the pantograph by the airflow is obviously unsteady and has a certain vibration frequency and amplitude, while the high-speed train passes through the tunnel. In addition to the unsteady behavior in the open-air operation, the compressive and expansion waves in the tunnel will be generated due to the influence of the blocking ratio. The propagation of the compression and expansion waves in the tunnel will affect the pantograph pressure distribution and cause the pantograph stress state to change significantly, which affects the current characteristics of the pantograph. In this paper, the aerodynamic force of the pantograph is studied with the method of the IDDES combined with overset grid technique when high speed train passes through the tunnel. The results show that the aerodynamic force of the pantograph is subjected to violent oscillations when the pantograph passes through the tunnel, especially at the entrance of the tunnel, the exit of the tunnel and the expansion wave passing through the pantograph. The changes of the pantograph aerodynamic force can reach a maximum amplitude of 106%. When high-speed trains pass through tunnels at different speeds, the aerodynamic coefficients of the pantographs are roughly the same.


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