Rotorcraft Engine Cycle Optimization at Mission Level

Abstract

Rotorcraft Engine Cycie Optimization at iVIission LevelThis work investigates the potential to reduce fuel consumption associated with civil rotorcraft operations at mission level, through optimization of the engine design point cycle parameters. An integrated simulation framework, comprising models applicable to rotorcraft flight dynamics, rotor blade aeroelasticity, and gas turbine performance, has been deployed. A comprehensive and computationally efficient optimization strategy, utilizing a novel particle-swarm method, has been structured. The developed methodology has been applied on a twin-engine light and a twin-engine medium rotorcraft configuration. The potential reduction in fuel consumption has been evaluated in the context of designated missions, representative of modern rotorcraft operations. Optimal engine design point cycle parameters, in terms of total mission fuel consumption, have been obtained. Pareto front models have been structured, describing the optimum interrelationship between maximum shaft power and mission fuel consumption. The acquired results suggest that, with respect to technological limitations, mission fuel economy can be improved with the deployment of design specifications leading to increased thermal efficiency, while simultaneously catering for sufficient performance to satisfy aii-worthiness certification requirements. The developed methodology enables the identification of optimum engine design specifications using a single design criterion; the respective trade-off between fuel economy and payload-range capacity, through maximum contingency shaft power, that the designer is prepared to accept. Aircraft-Engine Design and Trajectory Optimization.A substantial amount of literature is available in the public domain, dealing with the investigation of operational procedures for aircraft and rotorcraft, potentially optimum in terms of fuel bum and environmental impact. D'Ippolito et al. [2] demonstrated the applicability of design of experiment (DOE) methods coupled with response surface models (RSM) to the optimization of a category A take-off maneuver for a twin-engine light rotorcraft. Their modeling approach included the use of the EUROPA rotorcraft flight dynamics code [7], the engine performance simulation tool GSP [8], and the noise propagation analysis tool HELENA [9]. Their optimization strategy included the deployment of a Latin hypercube design (LHD) DOE approach coupled with least square fitting Taylor polynomials to structure the required RSMs.

On the Effects of Optimal Implementation of Variable Rotor Speed and Power Management on Hybrid-Electric Rotorcraft

“…This is done by combining the engine performance model (TURBOMATCH) with models for electric powertrain performance. TURBOMATCH, developed at Cranfield University [20], is a well-validated software that has been successfully deployed in several studies for turboshaft engines for rotorcraft applications [24,36]. It utilizes zero-dimensional aerothermal analysis, employing discrete component maps.…”

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

“…The numerical framework employed herein to simulate the performance of the helicopter, HECTOR, has been applied in the past to assess fuel consumption and NO x emissions at rotorcraft mission level [7]. It has been also employed in the optimization of conventional and regenerative powerplants in terms of rotorcraft operational and environmental performance [8,9]. In addition to this work, several studies have been conducted in the optimization of the helicopter flight path and operational procedures for environmental impact mitigation [10,11].…”

“…This software permits the comprehensive simulation of three-dimensional helicopter missions employing a cost-effective methodology. HECTOR has been validated and extensively used in previous rotorcraft studies [8,9]. The architecture of the code is shown in Fig.…”

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

“…The numerical framework employed herein to simulate the performance of the helicopter, HECTOR, has been applied in the past to assess fuel consumption and NO x emissions at rotorcraft mission level [7], and it has been also employed in the optimization of conventional and regenerative powerplant configurations in terms of rotorcraft operational and environmental performance [8,9]. In addition to this work, several studies have been conducted in the optimization of the helicopter flight path and operational procedures for environmental impact reduction [10,11].…”

“…HECTOR constitutes an integrated tool that comprises the Lagrangian rotor blade modal analysis method [5,12], a flight path profile analysis based on the World Geodetic System dated in 1984 (WGS 84) [13], a nonlinear trim procedure solving for the aeroelastic behavior of the main rotor [14,15], the in-house engine performance analysis code TURBOMATCH first developed by MacMillan [3], and the gas turbine emissions prediction tool HEPHAESTUS created by Celis [4]. This software has been validated and extensively used in previous rotorcraft studies [8,9]. The HECTOR architecture is shown in Fig.…”