Roberto d’Ippolito

Simulation Framework Development for Helicopter Mission Analysis

Helicopter mission performance analysis has always been an important topic for the helicopter industry. This topic is now raising even more interest as aspects related to emissions and noise gain more importance for environmental and social impact assessments. The present work illustrates the initial steps of a methodology developed in order to acquire the optimal trajectory of any specified helicopter under specific operational or environmental constraints. For this purpose, it is essential to develop an integrated tool capable of determining the resources required (e.g. fuel burnt) for a given helicopter trajectory, as well as assessing its environmental impact. This simulation framework tool is the result of a collaborative effort between Cranfield University (UK), National Aerospace Laboratory NLR (NL) and LMS International (BE). In order to simulate the characteristics of a specific trajectory, as well as to evaluate the emissions that are produced during the helicopter’s operation within the trajectory, three computational models developed at Cranfield University have been integrated into the simulation tool. These models consist of a helicopter performance model, an engine performance model and an emission indices prediction model. The models have been arranged in order to communicate linearly with each other. The linking has been performed with the deployment of the OPTIMUS process and simulation integration framework developed by LMS International. The optimization processes carried out for the purpose of this work have been based on OPTIMUS’ built-in optimizing algorithms. A comparative evaluation between the optimized and an arbitrarily defined baseline trajectory’s results has been waged for the purpose of quantifying the operational profit (in terms of fuel required) gained by the helicopter’s operation within the path of an optimized trajectory for a given constraint. The application of the aforementioned methodology to a case study for the purpose of assessing the environmental impact of a helicopter mission, as well as the associated required operational resources is performed and presented.Copyright

Simulation Framework Development for Aircraft Mission Analysis

Since the very beginning of first commercial flight operations, aircraft mission analysis has played a major role in minimizing costs, increasing performances and satisfying regulations. The operational trajectory of any aircraft must comply with several constraints that need to be satisfied during its operation. The nature of these constraints can vary from Air Traffic Control (ATC) regulations, to emissions regulations and any combination between these two. The development of an integrated tool capable of determining the resources required (fuel and operational time) for a given aircraft trajectory, as well as assessing its environmental impact, is therefore essential. The present work illustrates the initial steps of a methodology developed in order to acquire the optimal trajectory of any specified aircraft under specific operational or environmental constraints. The simulation framework tool is the result of a collaborative effort between Cranfield University (UK), National Aerospace Laboratory NLR (NL) and LMS International (BE). With this tool, the optimal trajectory for a given aircraft can be computed and its environmental impact assessed. In order to simulate the characteristics of a specific trajectory, as well as to evaluate the emissions that are produced during the aircraft operation within it, three computational models developed at Cranfield University have been integrated into the simulation tool. These models consist of an aircraft performance model, an engine performance model and an emission indices model. The linking has been performed with the deployment of the OPTIMUS process and simulation integration framework developed by LMS International. The optimization processes carried out were based on OPTIMUS’ built-in optimizing algorithms. A comparative evaluation between an arbitrarily defined baseline trajectory and optimized ones has been waged for the purpose of quantifying the operational profit (in terms of fuel required or operational time) gained by the aircraft operation within the path of an optimized trajectory. Trade-off studies between trajectories optimized for different operational and environmental constraints have been performed. The results of the optimizations revealed a substantial margin available for reduction in fuel consumption as well as required operational time compared to a notional baseline. The optimal trajectories for minimized environmental impact in terms of produced emissions have been acquired and their respective required resources (fuel required and operational time) have been evaluated.© 2010 ASME

Integrated Management of Automotive Product Heterogeneous Data: Application Case Study

The product development process (PDP) in innovative companies is becoming more and more complex, encompassing many diverse activities, and involving a big number of actors, spread across different professions, teams and organizations. One of the major problems is that development activities usually depend on many different inputs and influencing factors, and that the information that is needed in order to make the best possible decisions is either not documented or embodied in data that is spread over many different IT-systems. In this context a suitable knowledge management approach is required that must ensure the integration and availability of required information along with the federation and interoperability of the different Enterprise tools.

Design Space Exploration and Optimization of Conceptual Rotorcraft Powerplants

This paper demonstrates the application of an integrated rotorcraft multidisciplinary design and optimisation framework, deployed for the purpose of preliminary design and assessment of optimum regenerative powerplant configurations for rotorcraft. The proposed approach comprises a wide-range of individual modelling theories applicable to rotorcraft flight dynamics, gas turbine engine performance and weight estimation as well as a novel physics-based stirred reactor model, for the rapid estimation of various gas turbine gaseous emissions. A Single-Objective Particle Swarm Optimizer is coupled with the aforementioned rotorcraft multidisciplinary design framework. The overall methodology is deployed for the design space exploration and optimisation of a reference multipurpose twin-engine light civil rotorcraft, modelled after the Bo105 helicopter, employing two Rolls Royce Allison 250-C20B turboshaft engines. Through the implementation of single-objective optimization, notionally based optimum regenerative engine design configurations are acquired in terms of engine weight, mission fuel burn and mission gaseous emissions inventory, at constant technology level. The acquired optimum engine configurations are subsequently deployed for the design of conceptual regenerative rotorcraft configurations, targeting improved mission fuel economy, enhanced payload range capability as well as improvements in the rotorcraft overall environmental footprint, while maintaining the required airworthiness requirements. The proposed approach essentially constitutes an enabler in terms of focusing the multidisciplinary design of conceptual rotorcraft powerplants to realistic, three-dimensional operations and towards the realization of their associated engine design trade-offs at mission level.Copyright

Multidisciplinary design and optimisation of conceptual rotorcraft powerplants for operational performance and environmental impact

This paper demonstrates the application of an integrated rotorcraft multidisciplinary design and optimisation framework, deployed for the purpose of preliminary design and assessment of optimum regenerative powerplant configurations for rotorcraft applications. The proposed approach comprises a wide-range of individual modelling theories applicable to rotorcraft flight dynamics, gas turbine engine performance and weight estimation as well as a physics-based stirred reactor model, for the rapid estimation of various gas turbine gaseous emissions. A single-objective Particle Swarm Optimiser is coupled with the aforementioned rotorcraft design framework. The overall methodology is deployed for the design and optimisation of a reference multipurpose Twin-Engine-Light civil rotorcraft, modelled after the Bo105 helicopter, which employs two Rolls-Royce Allison 250-C20B turboshaft engines. Through the implementation of a single-objective optimisation strategy, notionally based optimum engine design configurations are acquired in terms of engine weight, mission fuel burn and mission gaseous emissions inventory at constant technology level. The acquired optimum regenerative engine configurations are subsequently deployed for the design of conceptual rotorcraft regenerative engine configurations, targeting improved mission fuel economy, enhanced payload-range capability as well as overall environmental impact, while maintaining the respective rotorcraft airworthiness requirements. The proposed methodology essentially constitutes as an enabler for designing rotorcraft powerplants within realistic, three-dimensional operations and towards realising their associated design trade-offs at mission level.

Multi-Objective Optimization of a Regenerative Rotorcraft Powerplant: Quantification of Fuel Economy and Environmental Impact

A computationally efficient and cost effective simulation framework has been proposed to perform a multidisciplinary design and optimization of a conceptual regenerative rotorcraft powerplant configuration at mission level. A generic rotorcraft model, representative of a modern twin-engine light civil rotorcraft has been investigated, operating under a representative passenger air taxi mission. The design space corresponding to the conceptual regenerative engine thermodynamic cycle parameters as well as engine and mission design outputs in terms of low pressure compressor pressure ratio, high pressure compressor pressure ratio, turbine entry temperature, mass flow, heat exchanger effectiveness, engine design point specific fuel consumption, engine weight, mission fuel burn and mission CO2 and NOx emissions has been thoroughly investigated through the application of a latin hypercube sampling, design of experiment approach. The interdependencies between the various engine design inputs/outputs are quantified by establishing the corresponding linear correlations between the aforementioned engine inputs/outputs as well as for the corresponding mission output parameters. A multi-objective Particle Swarm Optimizer is employed to derive Pareto front models quantifying the optimum interrelationship between the mission fuel burn and NOx emissions inventory. The acquired engine cycle design parameters corresponding to the span of the Pareto front suggest that the heat exchanger design effectiveness is the key design parameter representing the interdependency between engine fuel economy and environmental impact. The acquired optimum engine models, obtained from the Pareto front, are subsequently deployed for the design of conceptual rotorcraft engine configurations, targeting improved mission fuel economy, enhanced payload-range capability and overall environmental impact.Copyright

Helicopter Mission Analysis Using a Multidisciplinary Simulation Framework

This paper describes the work done and strong interaction between the Technology Evaluator (TE), Green Rotorcraft (GRC) Integrated Technology Demonstrator (ITD) and Sustainable and Green Engine (SAGE) ITD of the Clean Sky Joint Technology Initiative (JTI). The GRC and SAGE ITDs are responsible for developing new helicopter airframe and engine technologies respectively, whilst the TE has the distinctive role of assessing the environmental impact of these technologies at single flight (mission), airport and Air Transport System levels (ATS). The assessments reported herein have been performed by using a GRC-developed multidisciplinary simulation framework called PhoeniX (Platform Hosting Operational and Environmental Investigations for Rotorcraft) that comprises various computational modules. These modules include a rotorcraft performance code (EUROPA), an engine performance and emissions simulation tool (GSP) and a noise prediction code (HELENA). PhoeniX can predict the performance of a helicopter along a prescribed 4D trajectory offering a complete helicopter mission analysis. In the context of the TE assessments reported herein, two helicopter classes are examined namely a Twin Engine Light (TEL) configuration for Emergency Medical Service (EMS) and Police missions and a Single Engine Light (SEL) configuration for Passenger/Transport missions. The different technologies assessed reflect three simulation points which are the ‘Baseline’ Year 2000 technology, ‘Reference’ Y2020 technology, without Clean Sky benefits, and finally the ‘Conceptual’, reflecting Y2020 technology with Clean Sky benefits. The results of this study illustrate the potential that incorporated technologies possess in terms of improving performance and gas emission metrics such as fuel burn, CO2, NOx as well as the noise footprint on the ground.Copyright

Rotorcraft Engine Cycle Optimization at Mission Level

This 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 inter-relationship 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, whilst simultaneously catering for sufficient performance to satisfy airworthiness 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.Copyright