Automotive window seal design considering external aerodynamic load and surrogate constraint modeling

Verification of the behaviour of new designs of rotor seals is a crucial phase necessary for their use in rotary machines. Therefore, experimental equipment for the verification of properties that have an effect on rotor dynamics is being developed in the test laboratories of the manufacturers of these components all over the world. In order to be able to compare the analytically derived and experimentally identified values of the seal parameters, specific requirements for the rotor vibration pattern during experiments are usually set. The rotor vibration signal must contain the specified dominant components, while the others, usually caused by unbalance, must be attenuated. Technological advances have made it possible to use magnetic bearings in test equipment to support the rotor and as a rotor vibration exciter. Active magnetic bearings allow control of the vibrations of the rotor and generate the desired shape of the rotor orbit. This article presents a solution developed for a real test rig equipped with active magnetic bearings and rotor vibration sensors, which is to be used for testing a new design of rotor seals. Generating the exact shape of the orbit is challenging. The exact shape of the rotor orbit is necessary to compare the experimentally and numerically identified properties of the seal. The generalized notch filter method is used to compensate for the undesired harmonic vibrations. In addition, a novel modified generalized notch filter is introduced, which is used for harmonic vibration generation. The excitation of harmonic vibration of the rotor in an AMB system is generally done by injecting the harmonic current into the control loop of each AMB axis. The motion of the rotor in the AMB axis is coupled, therefore adjustment of the amplitudes and phases of the injected signals may be tedious. The novel general notch filter algorithm achieves the desired harmonic vibration of the rotor automatically. At first, the general notch filter algorithm is simulated and the functionality is confirmed. Finally, an experimental test device with an active magnetic bearing is used for verification of the algorithm. The measured data are presented to demonstrate that this approach can be used for precise rotor orbit shape generation by active magnetic bearings.

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Analytical predictor–corrector entry guidance for hypersonic gliding vehicles

International Journal of Nonlinear Sciences and Numerical Simulation ◽

10.1515/ijnsns-2019-0290 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Huatao Chen ◽

Kun Zhao ◽

Juan L.G. Guirao ◽

Dengqing Cao

Keyword(s):

Feedback Control ◽

Velocity Variation ◽

Analytical Relation ◽

Aerodynamic Load ◽

Quasi Equilibrium ◽

Bank Angle ◽

Entry Guidance ◽

Guidance Algorithm ◽

Predictor Corrector ◽

Guidance Problem

AbstractFor the entry guidance problem of hypersonic gliding vehicles (HGVs), an analytical predictor–corrector guidance method based on feedback control of bank angle is proposed. First, the relative functions between the velocity, bank angle and range-to-go are deduced, and then, the analytical relation is introduced into the predictor–corrector algorithm, which is used to replace the traditional method to predict the range-to-go via numerical integration. To eliminate the phugoid trajectory oscillation, a method for adding the aerodynamic load feedback into the control loop of the bank angle is proposed. According to the quasi-equilibrium gliding condition, the function of the quasi-equilibrium glide load along with the velocity variation is derived. For each guidance period, the deviation between the real-time load and the quasi-equilibrium gliding load is revised to obtain a smooth reentry trajectory. The simulation results indicate that the guidance algorithm can adapt to the mission requirements of different downranges, and it also has the ability to guide the vehicle to carry out a large range of lateral maneuvers. The feedback control law of the bank angle effectively eliminates the phugoid trajectory oscillation and guides the vehicle to complete a smooth reentry flight. The Monte Carlo test indicated that the guidance precision and robustness are good.

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Closed loop control of aerodynamic load fluctuations on wind turbine airfoil using surface plasma actuators

IFAC-PapersOnLine ◽

10.1016/j.ifacol.2020.12.1848 ◽

2020 ◽

Vol 53 (2) ◽

pp. 12675-12681

Author(s):

Dominique Nelson-Gruel ◽

Pierrick Joseph ◽

Alexis Paulh-Manssens ◽

Annie Leroy ◽

Sandrine Aubrun ◽

...

Keyword(s):

Wind Turbine ◽

Closed Loop ◽

Plasma Actuators ◽

Aerodynamic Load ◽

Closed Loop Control ◽

Surface Plasma ◽

Loop Control ◽

Wind Turbine Airfoil

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Seal design holds higher pressures

Sealing Technology ◽

10.1016/s1350-4789(97)84178-5 ◽

1997 ◽

Vol 1997 (37) ◽

pp. 5-6

Keyword(s):

Seal Design

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Pre-Deformation Method for Manufactured Compressor Blade Based on Load Incremental Approach

International Journal of Turbo and Jet Engines ◽

10.1515/tjj-2017-0024 ◽

2020 ◽

Vol 37 (3) ◽

pp. 259-265

Author(s):

Kang Da ◽

Wang Yongliang ◽

Zhong Jingjun ◽

Liu Zihao

Keyword(s):

Compressor Blade ◽

Aerodynamic Load ◽

Deformation Method ◽

Transonic Compressor ◽

Incremental Approach ◽

Compressor Rotor ◽

Centrifugal Load ◽

Blade Shape ◽

Stationary Shape ◽

Deformation Procedure

AbstractThe blade deformation caused by aerodynamic and centrifugal loads during operating makes blade configurations different from their stationary shape. Based on the load incremental approach, a novel pre-deformation method for cold blade shape is provided in order to compensate blade deformation under running. Effect of nonlinear blade stiffness is considered by updating stiffness matrix in response to the variation of blade configuration when calculating deformations. The pre-deformation procedure is iterated till a converged cold blade shape is obtained. The proposed pre-deformation method is applied to a transonic compressor rotor. Effect of load conditions on blade pre-deformation is also analyzed. The results show that the pre-deformation method is easy to implement with fast convergence speed. Neither the aerodynamic load nor centrifugal load can be neglected in blade pre-deformation.

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Investigation on flow field structure and aerodynamic load in vacuum tube transportation system

Journal of Wind Engineering and Industrial Aerodynamics ◽

10.1016/j.jweia.2021.104681 ◽

2021 ◽

Vol 215 ◽

pp. 104681

Author(s):

Sha Zhong ◽

Bosen Qian ◽

Mingzhi Yang ◽

Fan Wu ◽

Tiantian Wang ◽

...

Keyword(s):

Flow Field ◽

Transportation System ◽

Field Structure ◽

Aerodynamic Load ◽

Vacuum Tube

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Design of an Intermediate Turbine Duct Downstream of a High Pressure Turbine

Volume 2A: Turbomachinery ◽

10.1115/gt2016-56476 ◽

2016 ◽

Author(s):

Chaoshan Hou ◽

Hu Wu

Keyword(s):

High Pressure ◽

Three Dimensional ◽

Low Pressure ◽

Aerodynamic Load ◽

Duct Flow ◽

Original Design ◽

High Pressure Turbine ◽

Intermediate Turbine Duct ◽

Low Pressure Turbine ◽

Inlet Conditions

The flow leaving the high pressure turbine should be guided to the low pressure turbine by an annular diffuser, which is called as the intermediate turbine duct. Flow separation, which would result in secondary flow and cause great flow loss, is easily induced by the negative pressure gradient inside the duct. And such non-uniform flow field would also affect the inlet conditions of the low pressure turbine, resulting in efficiency reduction of low pressure turbine. Highly efficient intermediate turbine duct cannot be designed without considering the effects of the rotating row of the high pressure turbine. A typical turbine model is simulated by commercial computational fluid dynamics method. This model is used to validate the accuracy and reliability of the selected numerical method by comparing the numerical results with the experimental results. An intermediate turbine duct with eight struts has been designed initially downstream of an existing high pressure turbine. On the basis of the original design, the main purpose of this paper is to reduce the net aerodynamic load on the strut surface and thus minimize the overall duct loss. Full three-dimensional inverse method is applied to the redesign of the struts. It is revealed that the duct with new struts after inverse design has an improved performance as compared with the original one.

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Cable Suspension and Balance System with Low Support Interference and Vibration for Effective Wind Tunnel Tests

International Journal of Aeronautical and Space Sciences ◽

10.1007/s42405-021-00390-y ◽

2021 ◽

Author(s):

Keum-Yong Park ◽

Yeol-Hun Sung ◽

Jae-Hung Han

Keyword(s):

Wind Tunnel ◽

Vibration Suppression ◽

Aerodynamic Load ◽

Test Model ◽

Wind Tunnel Tests ◽

Balance System ◽

Motion Responses ◽

Vibration Responses ◽

Aerodynamic Interference ◽

Support Interference

AbstractA cable-driven model support concept is suggested and implemented in this paper. In this case, it is a cable suspension and balance system (CSBS), which has the advantages of low support interference and reduced vibration responses for effective wind tunnel tests. This system is designed for both model motion control and aerodynamic load measurements. In the CSBS, the required position or the attitude of the test model is realized by eight motors, which adjust the length, velocity, and acceleration of the corresponding cables. Aerodynamic load measurements are accomplished by a cable balance consisting of eight load cells connected to the assigned cables. The motion responses and load measurement outputs were in good agreement with the reference data. The effectiveness of the CSBS against aerodynamic interference and vibration is experimentally demonstrated through comparative tests with a rear sting and a crescent sting support (CSS). The advantages of the CSBS are examined through several wind tunnel tests of a NACA0015 airfoil model. The cable support of the CSBS clearly showed less aerodynamic interference than the rear sting with a CSS, judging from the drag coefficient profile. Additionally, the CSBS showed excellent vibration suppression characteristics at all angles of attack.

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