Analysis of the Equilibrium Manifold Linearization Model for Normal Shock Position Control

2006 ◽  
Author(s):  
Tao Cui ◽  
Daren Yu ◽  
Wen Bao
Keyword(s):  
Position Control ◽  
Normal Shock ◽  
Equilibrium Manifold ◽  
Shock Position

Normal shock wave/turbulent boundary-layer interaction control using ‘smart’ piezoelectric actuators

2005 ◽  
Vol 109 (1101) ◽  
pp. 577-583 ◽  
Author(s):  
J. S. Couldrick ◽  
S. L. Gai ◽  
J. F. Milthorpe ◽  
K. Shankar
Keyword(s):  
Boundary Layer ◽  
Shock Wave ◽  
Turbulent Boundary Layer ◽  
Piezoelectric Material ◽  
Active Control ◽  
Piezoelectric Actuators ◽  
Normal Shock ◽  
Normal Shock Wave ◽  
Boundary Layer Interaction ◽  
Shock Position

Abstract This paper looks at active control of the normal shock wave/turbulent boundary layer interaction (SBLI) using smart flap actuators. The actuators are manufactured by bonding piezoelectric material to an inert substrate to control the bleed/suction rate through a plenum chamber. The cavity allows rapid thickening of the boundary-layer approaching the shock, which splits into a series of weaker shocks forming a lambda shock foot, thus reducing wave drag. Active control allows optimisation of the interaction, as it would be capable of either positioning the control region around the original shock position using a series of unimorph flaps or fixing the shock position by controlling the rate of mass transfer. The level of control achieved by unimorph piezoelectric actuators is not large because of small amounts of deflection possible. It is believed that to provide optimal control a piezoelectric material, which can provide greater strain and hence higher amounts of deflection is needed. However, currently such a piezoelectric material is not commercially available.

The Shock Position in Overexpanded Nozzles.

1963 ◽  
Vol 67 (628) ◽  
pp. 268-269 ◽  
Author(s):  
M. Arens
Keyword(s):  
Nozzle Exit ◽  
Pressure Ratio ◽  
Separated Flow ◽  
Normal Shock ◽  
Nozzle Flow ◽  
Nozzle Pressure Ratio ◽  
Continuous Increase ◽  
Nozzle Pressure ◽  
Shock Position ◽  
Exit Mach Number

References 1 and 2 discuss the shock position in over-expanded nozzles, and in particular the transition from nozzle flow characterised by a normal shock in the nozzle to nozzle flow characterised by oblique shocks and separation from the wall. As is well known, the shock position and pressure distribution for unseparated overexpanded flow can be adequately explained using one-dimensional fluid mechanics. Ref. 2, while suggesting a criterion for transition to separated flow, maintains that the separation point is not predictable. The criterion suggested by ref. 2 is that whenever the pressure ratio p2/p0, associated with expansion to the nozzle exit plane followed by normal shock compression at the exit Mach number exceeds the nozzle pressure ratio pb/p0, separated flow will occur. Based on this criterion and the double valuedness of the p2/p0 locus, it is argued that at a nozzle pressure ratio of 0·624, a continuous increase of nozzle exit to throat area ratio will provide for transition from unseparated normal shock flow to separated flow and back to unseparated normal shock flow.

Study on integrated control for supersonic inlet and turbofan engine model

2020 ◽  
pp. 095441002094406
Author(s):  
Haoying Chen ◽  
Haibo Zhang ◽  
Yao Du ◽  
Qiangang Zheng
Keyword(s):  
Control Method ◽  
Integrated Control ◽  
Pressure Ratio ◽  
Normal Shock ◽  
Component Level ◽  
Recovery Coefficient ◽  
Turbofan Engine ◽  
Engine Model ◽  
Supersonic Inlet ◽  
Shock Position

Considering the supersonic inlet model with normal shock position feedback, the integrated control method of inlet and turbofan engine is studied. The integrated model includes the supersonic inlet model and the component level model of engine. Combining the relationship between the normal shock position and the total pressure recovery coefficient, the supersonic inlet and engine model is constructed. On the basis of this model, the normal shock position closed-loop control simulation is carried out, which shows that the normal shock position matching point could be stabilized near the optimal value while restraining the inlet stream disturbance. Furthermore, based on the H∞ control algorithm, an inlet and engine integrated control is designed to control the installation thrust and turbine pressure ratio with fuel, nozzle throat area, and normal shock position as control variables. The simulation results show that the response time of the integrated control is faster than the independent control. The integrated control has stronger ability to restrain the atmospheric disturbance, which could ensure the stable and reliable operation of the propulsion system.

205 A Position Control Test of Normal Shock Wave with Altitude Test Facility (ATF)

2010 ◽  
Vol 2010.45 (0) ◽  
pp. 210-211
Author(s):  
Takuya Mizuno ◽  
Yasushi Watanabe ◽  
Takeshi Tagashira
Keyword(s):  
Shock Wave ◽  
Position Control ◽  
Normal Shock ◽  
Test Facility ◽  
Control Test ◽  
Normal Shock Wave

scholarly journals Study on Inlet and Engine Integrated Model with Normal Shock Position Feedback

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Haoying Chen ◽  
Haibo Zhang ◽  
Zhihua Xi ◽  
Qiangang Zheng
Keyword(s):  
Flow Rate ◽  
Integrated Model ◽  
Normal Shock ◽  
Dynamic Identification ◽  
Component Level ◽  
Recovery Coefficient ◽  
Loop Control ◽  
Level Model ◽  
Shock Position ◽  
And Control

In order to consider the inlet and engine integrated model of supersonic airliner, the dynamic identification and control of inlet normal shock are studied. The research is based on the bleed air flow rate under supersonic conditions. With the two-dimensional CFD model of supersonic inlet, the dynamic and static effects of the bleeding flow rate on the normal shock position were investigated. The transfer function was identified, and simultaneously the paper carried out a comprehensive study of inlet and engine integrated model, which is established based on the inlet shock position model and engine component level model. The relationship between normal shock position and total pressure recovery coefficient has been taken into consideration in this model. Based on the inlet and engine integrated model, the closed-loop control simulation of normal shock position is carried out. The results show that the model could resist the disturbance of the inlet flow and keep the inlet and engine matching operation point stable near the optimal value.

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