An Analysis of the Static and Dynamic Stability of an Hypersonic Transport Aircraft Longitudinal Motion Flying at Hypersonic Speeds and Various Heights

2012 ◽  
Author(s):  
D. Mclean ◽  
Z.A. Zaludin ◽  
P.R. Arora

Suatu kajian tentang kestabilan statik dan dinamik pesawat pengangkutan hipersonik hipotesis telah dilakukan dengan menggunakan model matematik untuk pergerakan membujur semasa penerbangan di keadaan penerbangan yang berlainan. Hasil daripada analisis kestabilan menunjukkan bahawa pesawat tersebut akan menjadi lebih tidak stabil apabila penerbangan di nombor Mach dan ketinggian yang lebih tinggi daripada keadaan penerbangan nominal. Juga disertakan di sini keadaan enjin scramjet apabila pesawat ini terbang pada kelajuan hipersonik dan ketinggian yang berlainan. Kata kunci: dinamik pesawat; kestabilan dinamik; kestabilan statik; enjin scramjet A study of the static and dynamic stability of an hypothetical hypersonic transport aircraft was conducted based on a mathematical model of the longitudinal motion of the aircraft flying at a number of different flight conditions. The result from the stability analysis has shown that the aircraft becomes even less stable at higher Mach numbers and heights than the nominal flight condition. Also discussed here is the scramjet engine condition when the aircraft was simulated to be flying at hypersonic speeds and different heights. Key words: aircraft dynamics; dynamic stability; static stability; scramjet engine

Aviation ◽  
2016 ◽  
Vol 20 (4) ◽  
pp. 160-167 ◽  
Author(s):  
Agnieszka KWIEK

The purpose of this research is an analysis of the static and dynamic stability of the Modular Airplane System (MAS). The MAS is designed to perform suborbital space flights. The concept assumes that two tailless vehicles bonded together form a conventional aircraft where the wing of the second one is used as the horizontal tail of the whole system. The CFD calculations, and the stability and control derivatives were conducted by the PANUKL package, which uses a low order panel method for the aerodynamic analysis. The analysis of the static and dynamic stability was performed by the SDSA package. Only the selected part of the MAS mission was investigated. The results that will be presented have been divided into three parts: static stability, longitudinal dynamic stability and lateral dynamic stability. The MAS has a few possible applications. The first one is a suborbital space tourism flight. Moreover, it can be used as a lunching vehicle for micro satellites or as a testing platform for new space technology to improve their TRL level. Finally, in the far future, it could be used as a fast point-to-point travel system. The paper presents the results of the static and dynamic stability of a unique aircraft configuration which consists of two tailless vehicles. The research focuses on a situation where the vehicles are just before separation and their mass is similar. Moreover, the influence of the second vehicle’s position with respect to the first one is included.


2013 ◽  
Vol 572 ◽  
pp. 636-639
Author(s):  
Xi Chen ◽  
Gang Wang

This paper deals with the walking stability analysis of a multi-legged crablike robot over slope using normalized energy stability margin (NESM) method in order to develop a common stabilization description method and achieve robust locomotion for the robot over rough terrains. The robot is simplified with its static stability being described by NESM. The mathematical model of static stability margin is built so as to carry out the simulation of walking stability over slope for the crablike robot that walks in double tetrapod gait. As a consequence, the relationship between stability margin and the height of the robots centroid, as well as its inclination relative to the ground is calculated by the stability criterion. The success and performance of the stability criterion proposed is verified through MATLAB simulation and real-world experiments using multi-legged crablike robot.


Author(s):  
Budy D. Notohardjono ◽  
Robert Sanders

This paper discusses the static and dynamic stability analysis of rack or frame computer/server products during shipping and relocation. The static stability is the ability of server products to resist tipping over on a typical raised floor in a datacenter or when it is installed in its operational product environment. The dynamic stability is the ability to resist tipping over when a velocity change occurs during re-location either on flat or inclined planes. The product consists of a frame or a rack in which components such as processor units, input-output units and power supplies are installed. The static stability analysis presented here calculates the tip over threshold angle, which is the maximum angle of an inclined plane on which the product can be placed without tipping over. The location of the installed components in a frame, the dimension and weight of the installed components, and the dimension of the product dictate the overall static stability of the product. Specifically, those parameters affect the location of the center of gravity of the product and the tip over threshold angle. The tip over threshold angle is a critical parameter influencing the dynamic stability of the product.. The dynamic stability of an unpackaged product moving on casters can be calculated using the conservation of mechanical energy principle. Finite element modeling is a good way to evaluate the dynamic stability of a product during manual handling or mechanical handling; for instance, on a forklift. The objective of the finite element modeling is to provide guidelines on the maximum speed, minimum radius curvature, and safe turning speed of a forklift when transporting a product. The main objective of the analysis presented here is to provide a method for analyzing the static and dynamic stability of a rack style computer server product during shipping, relocation, and handling.


2019 ◽  
Vol 9 (19) ◽  
pp. 4135 ◽  
Author(s):  
Marco Bietresato ◽  
Fabrizio Mazzetto

In this study, a new rig for investigating the static and dynamic stability of agricultural machines was conceived: its architecture was studied and its layout was designed following a specific conceptual approach. The first part of the proposed design process specifically addresses the test equipment and follows a ‘top-down’ logic starting from the requisites of the tests to perform. This approach alternates analysis and synthesis phases and exploits two important principles of the creative design process: functional analysis and decomposition, and kinematic inversion. During this process, many solutions (kinematic mechanisms, actuators) were proposed and discussed based on their advantages and disadvantages towards the definition of an optimal configuration. Therefore, the layout of a new mechanical system has been developed, which is supposed to steer subsequent and more detailed design-phases appropriately. The proposed facility has many innovative features compared to traditional test systems, in which vehicles are tested for lateral overturning under static conditions with the steering components (wheels/central joint for conventional/articulated vehicles) usually in a configuration corresponding only to a straight-path trajectory. Indeed, the present test rig is a mechanical installation with three degrees of freedom. It presents a wide plane, which can be tilted, composed by two semi-platforms connected by a central articulation hinge, operated by hydraulic jacks which allow the different angulations of the semi-platforms. It is specifically thought for performing dynamic stability tests of vehicles, especially on circular trajectories. An additional subsystem embedded in one of the two semi-platforms, configured as a rotating platform (‘turntable’), can test the global (static) stability of motionless vehicles placed on it.


2020 ◽  
Vol 24 (5) ◽  
pp. 1053-1068
Author(s):  
Abdullo Majidov ◽  
◽  

The purpose of this work is to study the self-starting of induction motors for the auxiliary needs of power plants and substations as well as the mutual influence of motors on each other under short-term voltage dips and after voltage recovery on the buses to which these motors are connected. The object of the research is the operating VIII section with the capacity of 0.4 kV of the auxiliary service system with 9 induction motors of the heat and power plant no.1 in the city of Dushanbe (Republic of Tajikistan). Simulation modeling was carried out in the software package Electrical Transient Analyzer Program (USA) using algebraic and simplified differential equations to determine the values of indicators of static and dynamic stability of auxiliary needs of power plants and substations. As a result of modeling, the values of indicators of static and dynamic stability of the auxiliary needs system of power stations are determined. Based on the results obtained the margins of static and dynamic stability of auxiliary needs of power plants and substations are constructed and the conditions for implementing the optimal self-start, which allow to ensure uninterrupted operation of responsible mechanisms with induction motors at voltage dips are determined. The developed methods for studying the self-starting of power plant and substation auxiliary need induction motors ensures more accurate determination of the values of static stability voltages and dynamic stability time. The developed simulation model allows to specify and determine the success of induction motor self-starting in the systems of power plant and substation auxiliary needs. The developed methods are recommended for more precise selection of operating values for relay protection and automation as well as technological protection in the systems of auxiliary needs of power plants and substations with induction motors for more reliable operation of the main and auxiliary technological equipment.


Author(s):  
Gerry Willardoe Kayadoe ◽  
Heffry V. Dien ◽  
Revols D.Ch. Pamikiran

ABSTRACT The stability of a ship is one of the important technical factors in supporting successful fishing operations, and ultimately improving the welfare of fishermen; therefore a study on the stability of KM. Surya Prima had been done in the village of Borgo, District of Tanawangko, Minahasa Regency. Dynamic stability is the stability of the vessel measured by giving a force at the boat to form a certain rocking angle. This stability is expressed as an area under the curve of static stability. Dynamic ship stability calculation results will be compared with the stability criteria according to the International Maritime Organization (IMO) as in Fyson (1985) through the GZ curve. From the comparison it will get the level of dynamic stability of the vessel under study. Dynamic stability parameter values of Surya Prima purse seine vessel were: A (0-300) = 0.1179 m-rad., B (0-400) = 0.1935 m-rad., C (30-400) = 0.07552 m-rad., D (Angle GZmax) = 48 097, E (GZmin) = 0.475 m, F (GM) = 0965 m. Keywords: stability, curve, purse seiner   ABSTRAK Kestabilan kapal adalah salah satu faktor teknis penting dalam menunjang sukses operasi penangkapan ikan, dan pada akhirnya akan membantu meningkatkan kesejahteraan nelayan; oleh karena itu telah diadakan penelitian stabilitas KM. Surya Prima di Desa Borgo, Kecamatan Tanawangko, Kabupaten Minahasa. Stabilitas dinamis adalah stabilitas kapal yang diukur dengan jalan memberikan suatu usaha pada kapal sehingga membentuk sudut oleng tertentu. Stabilitas dinamis dinyatakan dalam luas area di bawah kurva stabilitas statis. Hasil perhitungan stabilitas dinamis kapal yang diukur dibandingkan dengan nilai kriteria kestabilan kapal oleh International Maritime Organization (IMO) dalam Fyson (1985) melalui kurva GZ. Dari perbandingan itu akan didapatkan tingkat kestabilan dinamis dari kapal yang diteliti. Nilai parameter kestabilan dinamis kapal pukat cincin Surya Prima adalah sebagai berikut: A (0-300) = 0.1179 m-rad., B (0-400) = 0.1935 m-rad., C (30-400) = 0.07552 m-rad., D (Sudut GZmax) = 48.097, E (GZmin) = 0.475 m, F (GM) = 0.965 m. Kata-kata kunci: stabilitas, kurva, pukat cincin


2019 ◽  
Vol 24 (3) ◽  
pp. 504-510
Author(s):  
Rakesh Ranjan Chand Chand ◽  
Pravat Kumar Behera ◽  
Madhusmita Pradhan ◽  
Pusparaj Dash

This research work is concerned with the static and dynamic stability study of an exponentially tapered revolving beam having a circular cross-section exposed to an axial live excitation and a variable temperature grade. The stability is analysed for clamped-clamped, clamped-pinned, and pinned-pinned end arrangements. Hamilton’s principle is used to develop the equation of motion and accompanying end conditions. Then, the non-dimensional form of the equation of motion and the end conditions are found. Galerkin’s process is used to find a number of Hill’s equations from the non-dimensional equations. The parametric instability regions are acquired by means of the Saito-Otomi conditions. The consequences of the variation parameter, revolution speed, temperature grade, and hub radius on the instability regions are examined for both static and dynamic load case and represented by a number of plots. The legitimacy of the results is tested by plotting different graphs between displacement and time using the Runge-Kutta fourth-order method. The results divulge that the stability is increased by increasing the revolution speed; however, an increase in the variation parameter leads to destabilization in the system and for same parameters, the stability is less in the case of a variable temperature grade than that of a constant temperature grade condition.


1976 ◽  
Vol 21 (3) ◽  
pp. 16-24
Author(s):  
Terri J. Horst ◽  
Robert J. Reschak

The development and application of a mathematical model for predicting sideslip during flight without a tail rotor are described in this paper. This method of analysis can he used to properly size a fin which will have sufficient static and dynamic stability to provide “fly‐back” capability if the tail rotor is lost, is damaged, or fails. It is well suited for preliminary design since it requires only a limited knowledge of the aerodynamic characteristics of the helicopter airframe. Sample calculations are shown for a modern attack helicopter.


Author(s):  
Andreas Rauch ◽  
William Singhose ◽  
Daichi Fujioka ◽  
Taft Jones

Mobile boom cranes are used throughout the world to perform important and dangerous manipulation tasks. The usefulness of these cranes is greatly improved if they can utilize their mobile base when they lift and transfer a payload. However, crane motion induces payload swing. The tip-over stability is degraded by the payload oscillations. This paper presents a process for conducting a stability analysis of such cranes. As a first step, a static stability analysis is conducted to provide basic insights into the effects of the payload weight and crane configuration. Then, a semi-dynamic method is used to account for payload swing. The results of a full-dynamic stability analysis using a multibody simulation of a boom crane are then compared to the outcomes of the simpler approaches. The comparison reveals that the simple semi-dynamic analysis provides good approximations for the tip-over stability properties. The results of the stability analyses are verified by experiments. The analysis in this paper provides useful guidance for the practical tip-over stability analysis of mobile boom cranes and motivates the need to control payload oscillation.


Author(s):  
SA Andrews ◽  
RE Perez

Recent studies of new, fuel-efficient transport aircraft have considered designs, which make use of two principal lifting surfaces to provide the required lift as well as trim and static stability. Such designs include open tandem-wings as well as closed joined and box-wings. As a group, these aircraft can be termed dual-wing designs. This study developed a new analytic model, which takes into account the downwash from the two main wings and is sensitive to three important design variables: the relative areas of each wing, the streamwise separation of the wings, and the center of gravity position. This model was used to better understand trends in the dual-wing geometry on the stability, maneuverability, and lift-to-drag ratio of the aircraft. Dual-wing aircraft have been shown to have reduced the induced drag compared to the conventional designs. In addition, further drag reductions can be realized as the horizontal tail can be removed if the dual-wings have sufficient streamwise stagger to provide the moments necessary for trim and longitudinal stability. As both wings in a dual-wing system carry a significant fraction of the total lift, trends in such designs that led to longitudinal stability can differ from those of the conventional aircraft and have not been the subject of detailed investigation. Results from the analytic model showed that the longitudinal stability required either a reduction of the fore wing area or shifting the center of gravity forward from the midpoint of both wings' aerodynamic centers. In addition, for wing configurations of approximately equal fore and aft wing areas, increasing the separation between the two wings decreased the stability of the aircraft. The source of this unusual behavior was the asymmetric distribution of downwash upstream and downstream of the wing. These relationships between dual-wing geometry and stability will provide initial guidance on the conceptual design of dual-wing aircraft and aid in the understanding of the results of more complex studies of such designs, furthering the development of future transport aircraft.


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