Level of self-excited vibrations of aerodynamic control surfaces during attached flow of a transonic gas flow past them

1991 ◽  
Vol 23 (4) ◽  
pp. 431-435
Author(s):  
A. V. Safronov
2020 ◽  
Vol 32 (8) ◽  
pp. 087108
Author(s):  
A. A. Abramov ◽  
A. V. Butkovskii ◽  
O. G. Buzykin

2018 ◽  
Vol 848 ◽  
pp. 756-787 ◽  
Author(s):  
A. Kluwick ◽  
E. A. Cox

The behaviour of steady transonic dense gas flow is essentially governed by two non-dimensional parameters characterising the magnitude and sign of the fundamental derivative of gas dynamics ($\unicode[STIX]{x1D6E4}$) and its derivative with respect to the density at constant entropy ($\unicode[STIX]{x1D6EC}$) in the small-disturbance limit. The resulting response to external forcing is surprisingly rich and studied in detail for the canonical problem of two-dimensional flow past compression/expansion ramps.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Guan Wang ◽  
Li Li ◽  
Weihua Li ◽  
Huajun Zhou ◽  
Changbo Ma ◽  
...  

This study investigates an adaptive controller for the flexible air-breathing hypersonic vehicles (AHVs) subject to external disturbances and actuator constraints. The combination of nonlinear disturbance observer and adaptive mechanism is exploited to design an adaptive controller for each subsystem. For the velocity subsystem, an auxiliary system is employed to handle the scramjet input saturation issue. For the altitude subsystem, the magnitude/rate constraints and the dynamics of aerodynamic control surfaces are addressed by the control allocation module. Simulations show the effectiveness of the proposed control.


Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5480
Author(s):  
Titilayo Ogunwa ◽  
Blake McIvor ◽  
Nurkhairunisa Awang Jumat ◽  
Ermira Abdullah ◽  
Javaan Chahl

The actuated abdomens of insects such as dragonflies have long been suggested to play a role in optimisation and control of flight. We have examined the effect of this type of actuation in the simplified case of a small fixed wing aircraft to determine whether energetic advantages exist in normal flight when compared to the cost of actuation using aerodynamic control surfaces. We explore the benefits the abdomen/tail might provide to balance level flight against trim changes. We also consider the transient advantage of using alternative longitudinal control effectors in a pull up flight maneuver. Results show that the articulated abdomen significantly reduces energy consumption and increase performance in isolated manoeuvres. The results also indicate a design feature that could be incorporated into small unmanned aircraft under particular circumstances. We aim to highlight behaviours that would increase flight efficiency to inform designers of micro aerial vehicles and to aid the analysis of insect flight behaviour and energetics.


1953 ◽  
Vol 24 (5) ◽  
pp. 584-589 ◽  
Author(s):  
Max M. Munk
Keyword(s):  
Gas Flow ◽  

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