Unsteady Characterization of Fluidic Flow Control Devices for Gust Load Alleviation

Asaro, Salvatore; Khalil, Khalid; Bauknecht, André

doi:10.1007/978-3-030-79561-0_15

Cited by 9 publications

(8 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For comparison, the fastest gust defined in the certification documentation at ground level, M ∞ = 0.35 and Re = 1.3 ⋅ 10 7 ( c = 2.29 m) generates a peak change in lift coefficient of Δc L = 0.38 at a slightly delayed time of Δt * g = 1.16 ( Δt * = 4.54 ), caused by unsteady aerodynamic effects. The highest gust load change ( Δc L = 0.68 ) at ground level is reached for the longest gust with Δt * g = 10.2 ( Δt * = 39.8 ), (Asaro et al 2021). Overall, the impulsive activation of the present actuation system appears to be fast enough to counteract even the shortest gusts encountered at ground level, but also features sufficient control authority to counteract the lift changes induced by the longest gusts.…”

Section: Jet Performance For Impulsive Activationmentioning

confidence: 78%

“…The correspondingly occurring increased momentum loss is not compensated by the small additional jet momentum and therefore results in earlier flow separation from the Coandă surface, as shown in Fig. 14 and discussed in more detail by Asaro et al (2021).…”

Section: Steady Actuator Performancementioning

confidence: 92%

“…For this reason the medium grid is selected for this study. Further details on the numerical setup can be found in Asaro et al (2021).…”

Section: Detachment Angle On the Coandă Surfacementioning

confidence: 99%

“…Unsteady RANS simulations of a symmetrical airfoil showed that adequate activation of a Coandă jet can lead to a near constant lift when the airfoil encounters a medium-amplitude 1-cos gust (Li and Qin 2020). Unsteady 2D-RANS simulations of a supercritical airfoil at different operating conditions indicated that an impulsive activation of a Coandă jet can reach lift reduction amplitudes within a reaction time that is suitable also for compensating the shortest 1-cos gusts (Asaro et al 2021). The fast onset of actuator-induced lift was further illustrated by an experimental study of a cambered airfoil at low Reynolds number.…”

Section: Introductionmentioning

confidence: 99%

“…GLA operation, resulting in c requirements that are between two and nine times smaller than for the normal jet (Asaro et al 2021). For this reason, the focus of the present study is on the Coandă actuator as the most promising candidate for active GLA.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Experimental load modification on a dual-slot circulation control airfoil

2022

Self Cite

View full text Add to dashboard Cite

Active load alleviation can substantially contribute to decrease structural weight and emissions of future transport aircraft by limiting peak aerodynamic loads that the aircraft experiences during flight. Fluidic actuators, as part of active load alleviation systems, have the potential for faster and more complete gust load reduction. The performance of a dual slot circulation control airfoil for gust load alleviation is investigated experimentally on a supercritical airfoil model. The tests are conducted in a low-speed wind tunnel at a chord-based Reynolds number of $${\text{Re}}={\text{1.5}}\cdot {\text{10}}^{{\text{6}}}$$ Re = 1.5 · 10 6 and $${\it{M}}_{{\infty }}={\text {0.14}}$$ M ∞ = 0.14 . The model features an elliptical Coandă geometry integrated into the airfoil’s trailing edge to minimize cruise performance penalty, while still allowing for substantial load reduction. Blowing from a single slot, as well as simultaneously from pressure and suction side slots is tested over a range of blowing rates to assess the impact on load modification. Both steady and impulsive activation performance are evaluated based on surface pressure, integral load, and flow field measurements around the Coandă geometry. High control authority is found for upper and lower single slot blowing, with peak changes in lift coefficient of about $$\pm\,{0.33}$$ ± 0.33 and lift-to-equivalent-drag ratio change of up to 100. Similar peak lift changes and reduced equivalent drag are obtained by adding marginal ($$< 14\%$$ < 14 % of total) blowing from the opposite slot, which also reduces pitching moment changes for primary upper and marginal lower blowing. Impulsive jet activation exhibits load control authority comparable to steady actuation and sufficiently short onset times to counteract all gusts defined by certification documentation.

show abstract

Section: Jet Performance For Impulsive Activationmentioning

confidence: 78%

Section: Steady Actuator Performancementioning

confidence: 92%

“…For this reason the medium grid is selected for this study. Further details on the numerical setup can be found in Asaro et al (2021).…”

Section: Detachment Angle On the Coandă Surfacementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Experimental load modification on a dual-slot circulation control airfoil

2022

Self Cite

View full text Add to dashboard Cite

show abstract

Unsteady nonlinear lifting line model for active gust load alleviation of airplanes

Beyer,

Ullah,

Steen

et al. 2024

CEAS Aeronaut J

View full text Add to dashboard Cite

Active gust load alleviation is an important technology for designing future passenger airplanes to be lighter and thus more environmentally friendly. Unsteady Reynolds-averaged Navier–Stokes (URANS) simulations are typically used to accurately calculate gust loads, but because of their high computational cost, they can only be performed at a few selected operating points. In simpler potential theory models, stall is neglected, resulting in loss of accuracy. In this paper, a low-order unsteady aerodynamics wing model is presented, which is able to represent well compressible flow with stall. Furthermore, the model offers the possibility to modularly incorporate actuators, which allows the design and evaluation of active load alleviation systems. The model is based on a conventional unsteady 2D airfoil model including a dynamic stall model. The dynamic stall model requires viscous steady coefficients, e.g. from 2D steady RANS computations. This 2D airfoil model is coupled with a 3D steady-state lifting line model. The model is applied to the LEISA research airplane and extensively validated with URANS results. It performs well in calculating gust loads with and without simultaneous flap deflections, and provides significantly more accurate results in the case of stall than when stall is neglected.

show abstract

Flow simulation of the flight manoeuvres of a large transport aircraft with load alleviation

Breitenstein

Radespiel

2021

Aeronaut. j.

View full text Add to dashboard Cite

A new method for predicting manoeuvre loads on a large transport aircraft with a swept-back wing and a load alleviation system based on control surface deflections is developed. For this purpose, three-dimensional Reynolds-averaged Navier–Stokes (RANS) simulations of the rigid wing–fuselage configuration are performed while the aerodynamics of the tailplane are estimated by means of handbook methods. For a closer analysis, different quasi-steady pitching manoeuvres are chosen based on the CS-25 regulations. One of these manoeuvres is also simulated with active load alleviation, leading to a reduction in the wing-root bending moment by more than 40%. Besides demonstrating the potential of the considered load alleviation system, it is shown which manoeuvres are especially critical in this context and which secondary effects come along with load alleviation.

show abstract

Unsteady Characterization of Fluidic Flow Control Devices for Gust Load Alleviation

Cited by 9 publications

References 6 publications

Experimental load modification on a dual-slot circulation control airfoil

Experimental load modification on a dual-slot circulation control airfoil

Unsteady nonlinear lifting line model for active gust load alleviation of airplanes

Flow simulation of the flight manoeuvres of a large transport aircraft with load alleviation

Contact Info

Product

Resources

About