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Peiqing Liu

Bio: Peiqing Liu is an academic researcher from Beihang University. The author has contributed to research in topics: Aerodynamics & Airfoil. The author has an hindex of 13, co-authored 120 publications receiving 699 citations.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the aerodynamics and flow physics of a NACA 4412 airfoil in ground effect for a wide range of angles of attack from −4 to 20 degrees are investigated by numerical simulations.
Abstract: The aerodynamics and flow physics of a NACA 4412 airfoil in ground effect for a wide range of angles of attack from −4 to 20 deg are investigated by numerical simulations. The compressible Reynolds-averaged Navier–Stokes equations and shear-stress transport k-ω turbulence model equations are solved using the finite-volume method. Analyses of the computed results show that the angle of attack versus height (above the ground) plane can be divided into three regions based on the sign of the lift increment value: region I of positive ground effect, and regions II and III of negative ground effect. For low-to-moderate angles of attack, when the ride height is reduced, the airflow is blocked in the convergent passage between the lower surface of the airfoil and the ground, resulting in increase of pressure on the lower surface of the airfoil. As a consequence, the effective angle of attack decreases, and there is less upward deflection of the streamlines, resulting in an increase in pressure on the upper surfac...

67 citations

Journal ArticleDOI
TL;DR: In this article, a NACA 4412 airfoil is simulated numerically to investigate the influence of dynamic ground effect (DGE) on the aerodynamic and flow physics.

45 citations

Journal ArticleDOI
TL;DR: In this article, a flexible variable camber trailing-edge flap is introduced, capable of changing its shape smoothly from 50% flap chord to the rear of the flap, which can improve flight efficiency during takeoff, cruise and landing states.

41 citations

Journal ArticleDOI
TL;DR: In this article, the authors used sliding mesh technology to simulate the relative motion between a wing-in-ground-effect craft and wavy ground and analyzed the aerodynamic characteristics and flowfield.
Abstract: The flow around a wing-in-ground-effect craft flying at α=3 deg and α=9 deg over flat and wavy ground is simulated and investigated by using ANSYS FLUENT, employing the compressible Reynolds-averaged Navier–Stokes equations and the Spalart–Allmaras turbulence model. The sliding mesh technology is used to simulate the relative motion between the wing-in-ground-effect craft and wavy ground. The effects of the wavy ground, flight height, and angle of attack on the aerodynamic characteristics and flowfield are analyzed in detail. The aerodynamic forces are found to be periodic when the wing-in-ground-effect craft flies over wavy ground. The aerodynamic forces over both flat and wavy ground vary with flight height in the same pattern. As the flight height reduces, the lift, drag, and nose-down pitching moment all increase at both angles of attack (α=3 deg and α=9 deg); however, the lift-to-drag ratio increases for all flight heights at α=3 deg, while it first increases and then decreases at α=9 deg. Redu...

41 citations

Journal ArticleDOI
Ling Li1, Peiqing Liu1, Hao Guo1, Yujia Hou1, Xin Geng1, Jinjun Wang1 
TL;DR: In this paper, a test section in D5 aeroacoustic wind tunnel at Beihang University is recently upgraded for the aero-acoustic measurement of 30P30N high-lift configuration.

39 citations


Cited by
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Book ChapterDOI
30 Dec 2011
TL;DR: This table lists the most common surnames in the United States used to be Anglicised as "United States", then changed to "United Kingdom" in the 1990s.
Abstract: OUTPU T 29 OUTPU T 30 OUTPU T 31 OUTPU T 32 OUTPU T 25 OUTPU T 26 OUTPU T 27 OUTPU T 28 OUTPU T 21 OUTPU T 22 OUTPU T 23 OUTPU T 24 OUTPU T 17 OUTPU T 18 OUTPU T 19 OUTPU T 20 OUTPU T 13 OUTPU T 14 OUTPU T 15 OUTPU T 16 OUTPU T 9 OUTPU T 10 OUTPU T 11 OUTPU T 12 OUTPU T 5 OUTPU T 6 OUTPU T 7 OUTPU T 8 OUTPU T 1 OUTPU T 2 OUTPU T 3 OUTPU T 4 29 30 31 32 25 26 27 28 21 22 23 24 17 18 19 20 13 14 15 16 9

1,662 citations

Journal ArticleDOI
TL;DR: Experimental results achieved while diagnosis defects of centrifugal pump show that the proposed improved CNN has a significant improvement of identification accuracy of about 3.2% over traditional CNN.

92 citations

Journal ArticleDOI
TL;DR: The main feature of this work stems from the use of multiply advanced techniques or methodologies that enables the finite-time stability of the closed-loop attitude control system and the designed control scheme is continuous with the property of chattering restraining.
Abstract: This work addresses the challenging problem of finite-time fault tolerant attitude stabilization control for the rigid spacecraft attitude control system without the angular velocity measurements, in the presence of external disturbances and actuator failures. Consider the severe circumstances with above failures and uncertainties, a novel continuous finite-time Extended State Observer is first established to observe the attitude angular velocity and the synthetic failure simultaneously. Unlike the existing observers, the finite-time methodology and Extended State Observer are utilized, to achieve the finite-time uniformly ultimately bounded stability of the attitude angular velocity and extended state observation errors. Furthermore, a novel continuous finite-time attitude controller is developed by using the nonsingular terminal sliding mode control and super-twisting method. The main feature of this work stems from our use of multiply advanced techniques or methodologies that enables the finite-time stability of the closed-loop attitude control system and the designed control scheme is continuous with the property of chattering restraining. Finally, numerical simulation results are presented to illustrate the effectiveness and fine performances of the finite-time observer and controller for the attitude control system.

80 citations

Journal ArticleDOI
TL;DR: In this paper, the upward-parabola blowing jet flow control strategy for VAWTs is proposed to suppress the flow separation in advance, which can significantly enhance the aerodynamic performance by using significantly low energy consumption.

75 citations

Journal ArticleDOI
TL;DR: In this paper, the aerodynamics and flow physics of a NACA 4412 airfoil in ground effect for a wide range of angles of attack from −4 to 20 degrees are investigated by numerical simulations.
Abstract: The aerodynamics and flow physics of a NACA 4412 airfoil in ground effect for a wide range of angles of attack from −4 to 20 deg are investigated by numerical simulations. The compressible Reynolds-averaged Navier–Stokes equations and shear-stress transport k-ω turbulence model equations are solved using the finite-volume method. Analyses of the computed results show that the angle of attack versus height (above the ground) plane can be divided into three regions based on the sign of the lift increment value: region I of positive ground effect, and regions II and III of negative ground effect. For low-to-moderate angles of attack, when the ride height is reduced, the airflow is blocked in the convergent passage between the lower surface of the airfoil and the ground, resulting in increase of pressure on the lower surface of the airfoil. As a consequence, the effective angle of attack decreases, and there is less upward deflection of the streamlines, resulting in an increase in pressure on the upper surfac...

67 citations