Preliminary Study on a Wide-Speed-Range Helicopter Rotor/Turboshaft System

Garavello, Andrea; Benini, Ernesto

doi:10.2514/1.c031526

Cited by 22 publications

(11 citation statements)

References 2 publications

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“…This is especially critical for the analysis of helicopter performance, where high and low power conditions are expected at different phases of the mission. The results obtained from two previous simulations performed by Ballin [24] and Garavello et al [26] are also included in Fig. 6, and show similar trends to those obtained in this work.…”

Section: Engine Performance Simulationsupporting

confidence: 86%

Impact of Adverse Environmental Conditions on Rotorcraft Operational Performance and Pollutant Emissions

Ortiz-Carretero

Pardo

Goulos

et al. 2017

Journal of Engineering for Gas Turbines and Power

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It is anticipated that the contribution of rotorcraft activities to the environmental impact of civil aviation will increase in the future. Due to their versatility and robustness, helicopters are often operated in harsh environments with extreme ambient conditions. These severe conditions, not only affect the performance of the engine, but also the aerodynamics of the rotorcraft. This impact is reflected in the fuel burn and pollutants emitted by the rotorcraft during a mission. The aim of this paper is to introduce an exhaustive methodology to quantify the influence adverse environment conditions have in the mission fuel consumption and the associated emissions of nitrogen oxides (NO x ). An Emergency Medical Service (EMS) and a Search and Rescue (SAR) mission are used as case studies to simulate the effects of extreme temperatures, high altitude, and compressor degradation on a representative Twin-Engine Medium (TEM) weight helicopter, the Sikorsky UH-60A Black Hawk. A simulation tool for helicopter mission performance analysis developed and validated at Cranfield University was employed. This software comprises different modules that enable the analysis of helicopter flight dynamics, powerplant performance and exhaust emissions over a user defined flight path profile. For the validation of the models implemented, extensive comparisons with experimental data are presented throughout for rotorcraft and engine performance as well as NO x emissions. Reductions as high as 12% and 40% in mission fuel and NO x emissions, respectively, were A Main rotor disk area [m 2 ] C p =P MR /ρA(ΩR) 3 Power coefficient [-] C t = T MR /ρA(ΩR) 2 Thrust coefficient [-] P MR Main rotor power [W] R Main rotor radius [m] T MR Main rotor thrust [N] V Air speed [m/s] V NOx Airspeed for minimum NO x [m/s] V rg Airspeed for maximum range [m/s] w f Powerplant fuel flow [g/s] w NOx Powerplant NO x production [g/s] Greek symbols Γ Mass flow capacity [-] Δ Increment [%] Ω Main rotor rotational speed [rad/s] η Isentropic efficiency [-] ρ Air density [kg/m 3 ] σ Main rotor solidity [-] ω Blade natural frequency [rad/s]

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Section: Engine Performance Simulationsupporting

confidence: 86%

Impact of Adverse Environmental Conditions on Rotorcraft Operational Performance and Pollutant Emissions

Ortiz-Carretero

Pardo

Goulos

et al. 2017

Journal of Engineering for Gas Turbines and Power

View full text Add to dashboard Cite

show abstract

“…This is especially critical for the analysis of helicopter performance, where high and low power conditions are expected at different phases of the mission. The results obtained from two previous simulations performed by Ballin [21] and Garavello et al [23] are also provided for comparison, and are very similar to the results obtained in this work.…”

Section: Figuresupporting

confidence: 86%

Assessment of the Effect of Environmental Conditions on Rotorcraft Pollutant Emissions at Mission Level

Ortiz-Carretero

Pardo

Pachidis

et al. 2017

Volume 1: Aircraft Engine; Fans and Blowers; Marine; Honors and Awards

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It is anticipated that the contribution of rotorcraft activities to the environmental impact of civil aviation will increase in the forthcoming future. Due to their versatility and robustness, helicopters are often operated in harsh environments with extreme ambient conditions and dusty air. These severe conditions affect not only the engine operation but also the performance of helicopter rotors. This impact is reflected in the fuel burn and pollutants emitted by the helicopter during a mission. The aim of this paper is to introduce an exhaustive methodology to quantify the influence of the environment in the mission fuel consumption and the associated emissions of nitrogen oxides (NOx). An Emergency Medical Service (EMS) and a Search and Rescue (SAR) mission were used as a case study to simulate the effects of extreme temperatures, high altitude and compressor degradation on a representative Twin-Engine Medium (TEM) weight helicopter, the Sikorsky UH-60A Black Hawk. A simulation tool for helicopter mission performance analysis developed and validated at Cranfield University was employed. This software comprises different modules that enable the analysis of helicopter flight dynamics, powerplant performance and exhaust emissions over a user defined flight path profile. The results obtained show that the environmental effects on mission fuel and emissions are mainly driven by the modification of the engine performance for the particular missions simulated. Fluctuations as high as 12% and 40% in mission fuel and NOx emissions, respectively, were observed under the environmental conditions simulated in the present study.

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“…An eight-DOF model for the PZL Mi-2 Plus helicopter (three translations and three rotations of a rigid fuselage, main rotor speed, and engine output power) was developed to optimize autorotation profiles with different performance indices, finally comparing the results with flight test data [16]. The above-mentioned autorotation control models can be regarded as being specific for investigation of optimized profiles after engine failures; however, they are not sufficient for designing flight or engine control law during autorotation [17][18][19][20][21]. This motivates the need for more It is meaningful to emphasize the significance and necessity of autorotation power recovery simulation and control.…”

Section: Introductionmentioning

confidence: 99%

Engine Control Design Using Compressor Guided Vanes During Autorotation Power Recovery

Sun

Zhang

2016

Arab J Sci Eng

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In order to improve the helicopter responsive ability during autorotation power recovery maneuvers, a new turbo-shaft engine control scheme is proposed in this paper. Using rotor flapping/lagging dynamics and an induced velocity model which is capable of capturing vortex ring characteristics, an integrated helicopter and engine model was developed to simulate autorotation process. By introducing a closed-loop with compressor guided vanes, a novel two-variable engine control law is devised using Linear Matrix Inequality Pole Placement method. This allows for a rapid adaptation of the helicopter to a large and fast needed torque variation required in autorotation power recovery. The transient performances and the robustness for the closedloop helicopter-pilot system are validated for some examples appropriated to autorotation training procedure. Simulation results illustrate that, with this novel control law, the helicopter's ability to respond during autorotation is strongly enhanced when compared to traditional cases.

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Preliminary Study on a Wide-Speed-Range Helicopter Rotor/Turboshaft System

Cited by 22 publications

References 2 publications

Impact of Adverse Environmental Conditions on Rotorcraft Operational Performance and Pollutant Emissions

Impact of Adverse Environmental Conditions on Rotorcraft Operational Performance and Pollutant Emissions

Assessment of the Effect of Environmental Conditions on Rotorcraft Pollutant Emissions at Mission Level

Engine Control Design Using Compressor Guided Vanes During Autorotation Power Recovery

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