EPISTLE: High lift system design for low-noise applied to a supersonic aircraft

2006 ◽  
Vol 110 (1107) ◽  
pp. 327-331 ◽  
Author(s):  
U. Herrmann
Keyword(s):  
System Design ◽  
Aircraft Design ◽  
Reynolds Numbers ◽  
Low Noise ◽  
High Lift ◽  
New Approach ◽  
Low Speed ◽  
Supersonic Aircraft ◽  
Preliminary Aircraft Design ◽  
High Reynolds

Abstract A new approach for low-drag high-lift system design based on the application of viscous flow solvers was developed in the EC research project EPISTLE. Two high-lift systems for a supersonic commercial transport aircraft (SCT) wing were designed, manufactured and wind-tunnel tested. The predicted large drag reductions were fully confirmed by tests at high Reynolds numbers. These drag reductions significantly reduce the low-speed noise of future SCT configurations. This was estimated by preliminary aircraft design tools. Low-speed noise reduction by aerodynamic means is obtained, as effective high-lift systems enable these aircraft to climb faster.

Separation and Transition Control on an Aft-Loaded Ultra-High-Lift LP Turbine Blade at Low Reynolds Numbers: High-Speed Validation

2006 ◽  
Vol 129 (2) ◽  
pp. 340-347 ◽  
Author(s):  
Maria Vera ◽  
Xue Feng Zhang ◽  
Howard Hodson ◽  
Neil Harvey
Keyword(s):  
Surface Roughness ◽  
Mach Number ◽  
Surface Finish ◽  
High Speed ◽  
Reynolds Numbers ◽  
High Lift ◽  
Low Reynolds Numbers ◽  
Low Speed ◽  
Transition Mechanism ◽  
Low Reynolds

This paper presents the second part of an investigation of the combined effects of unsteadiness and surface roughness on an aft-loaded ultra-high-lift low-pressure turbine (LPT) profile at low Reynolds numbers. The investigation has been performed using low- and high-speed cascade facilities. The low- and high-speed profiles have been designed to have the same normalized isentropic Mach number distribution. The low-speed results have been presented in the first part (Zhang, Vera, Hodson, and Harvey, 2006, ASME J. Turbomach., 128, pp. 517–527). The current paper examines the effect of different surface finishes on an aft-loaded ultra-high-lift LPT profile at Mach and Reynolds numbers representative of LPT engine conditions. The surface roughness values are presented along with the profile losses under steady and unsteady inflow conditions. The results show that the use of a rough surface finish can be used to reduce the profile loss. In addition, the results show that the same quantitative values of losses are obtained at high- and low-speed flow conditions. The latter proves the validity of the low-speed approach for ultra-high-lift profiles for the case of an exit Mach number of the order of 0.64. Hot-wire measurements were carried out to explain the effect of the surface finish on the wake-induced transition mechanism.

scholarly journals Guidelines for the LTO Noise Assessment of Future Civil Supersonic Aircraft in Conceptual Design

Aerospace ◽  
2022 ◽  
Vol 9 (1) ◽  
pp. 27
Author(s):  
Grazia Piccirillo ◽  
Nicole Viola ◽  
Roberta Fusaro ◽  
Luigi Federico
Keyword(s):  
Conceptual Design ◽  
Aircraft Design ◽  
Low Noise ◽  
Aircraft Noise ◽  
Noise Model ◽  
Noise Power ◽  
Community Noise ◽  
Prediction Program ◽  
Supersonic Aircraft ◽  
Noise Assessment

One of the most critical regulatory issues related to supersonic flight arises from limitations imposed by community noise acceptability. The most efficient way to ensure that future supersonic aircraft will meet low-noise requirements is the verification of noise emissions from the early stages of the design process. Therefore, this paper suggests guidelines for the Landing and Take-Off (LTO) noise assessment of future civil supersonic aircraft in conceptual design. The supersonic aircraft noise model is based on the semi-empirical equations employed in the early versions of the Aircraft NOise Prediction Program (ANOPP) developed by NASA, whereas sound attenuation due to atmospheric absorption has been considered in accordance with SAE ARP 866 B. The simulation of the trajectory leads to the prediction of the aircraft noise level on ground in terms of several acoustic metrics (LAmax, SEL, PNLTM and EPNL). Therefore, a dedicated validation has been performed, selecting the only available supersonic aircraft of the Aircraft Noise and Performance database (ANP), that is, the Concorde, through the matching with Noise Power Distance (NPD) curves for LAmax and SEL, obtaining a maximum prediction error of ±2.19%. At least, an application to departure and approach procedures is reported to verify the first noise estimations with current noise requirements defined by ICAO at the three certification measurement points (sideline, flyover, approach) and to draw preliminary considerations for future low-noise supersonic aircraft design.

Separation and Transition Control on an Aft-Loaded Ultra-High-Lift LP Turbine Blade at Low Reynolds Numbers: High-Speed Validation

2005 ◽  
Author(s):  
Maria Vera ◽  
Xue Feng Zhang ◽  
Howard Hodson ◽  
Neil Harvey
Keyword(s):  
Surface Roughness ◽  
Mach Number ◽  
Surface Finish ◽  
High Speed ◽  
Reynolds Numbers ◽  
High Lift ◽  
Low Reynolds Numbers ◽  
Low Speed ◽  
Transition Mechanism ◽  
Low Reynolds

This paper presents the second part of an investigation of the combined effects of unsteadiness and surface roughness on an aft-loaded ultra high lift low pressure turbine (LPT) profile at low Reynolds numbers. The investigation has been performed using low-speed and high-speed cascade facilities. The low speed and the high speed profiles have been designed to have the same normalized isentropic Mach number distribution. The low speed results have been presented in Part 1 of this paper. The current paper examines the effect of different surface finishes on an aft-loaded ultra-high-lift LPT profile at Mach and Reynolds numbers representative of LPT engine conditions. The surface roughness values are presented along with the profile losses under steady and unsteady inflow conditions. The results show that the use of a rough surface finish might reduce the profile loss. In addition, the results show that the same quantitative values of losses are obtained at high and low speed flow conditions. The latter proves the validity of the low speed approach for ultra high lift profiles for the case of an exit Mach number of the order of 0.64. Hot wire measurements were carried out to explain the effect of the surface finish on the wake induced transition mechanism.

Separation and Transition Control on an Aft-Loaded Ultra-High-Lift LP Turbine Blade at Low Reynolds Numbers: Low-Speed Investigation

2005 ◽  
Author(s):  
Xue Feng Zhang ◽  
Maria Vera ◽  
Howard Hodson ◽  
Neil Harvey
Keyword(s):  
Turbine Blade ◽  
Separation Bubble ◽  
Reynolds Numbers ◽  
Surface Boundary ◽  
Suction Surface ◽  
High Lift ◽  
Low Reynolds Numbers ◽  
Low Speed ◽  
Profile Losses ◽  
Low Reynolds

An experimental study was conducted to improve the performance of an aft-loaded ultra-high-lift low-pressure turbine blade known as U2 at low Reynolds numbers. This was achieved by manipulation of the laminar-turbulent transition process on the suction surface. The U2 profile was designed to meet the targets of reduced cost, weight and fuel burn of aircraft engines. The studies were conducted on both low-speed and high-speed experimental facilities under the unsteady flow conditions with upstream passing wakes. The current paper presents the low-speed investigation results. On the smooth suction surface, the incoming wakes are not strong enough to suppress the separation bubble due to the strong adverse pressure gradient on the suction surface and the low wake passing frequency, which allows the separation between the wakes more time to re-establish. Therefore, the profile losses of this ultra-high-lift blade are not as low as conventional or high-lift blades at low Reynolds numbers even in unsteady flows. Two different types of passive separation control devices, i.e. surface trips and air jets, were investigated to further improve the blade performance. The measurement results show that the profile losses can be further reduced to the levels similar to those of the high-lift and conventional blades due to the aft-loaded nature of this ultra-high-lift blade. Detailed surveys of the blade surface boundary layer developments showed that the loss reduction was due to the suppression of the separation underneath the wakes, the effect of the strengthened calmed region and the smaller separation bubble between wakes.

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