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Proposing Institution

Lehrstuhl für Hubschraubertechnologie,TUM
Project Manager

Stefan Platzer
Boltzmannsraße 15
85748 Garching
Rotorcraft regularly operate in complex flight conditions, such as hover over inclined ground planes (i.e. hillsides) or moving surfaces (e.g. ship decks). However, only little is known about the complex three-dimensional flow field in the rotor wake and the associated inflow distribution in the rotor plane in these flight conditions. Significant training as well as expensive flight tests are required to mitigate the risk of helicopter operations around ships / at hillsides, and advanced flight control systems are desirable to increase safety and reduce pilot workload. Therefore, there is a need for accurate, computationally efficient mathematical models capable of simulating these complex flow environments, in particular the rotor inflow because it changes a rotorcraft’s flight dynamics. Dynamic inflow-type models could fill this role. However, a prerequisite to develop such models is an understanding of the complex three-dimensional fluid dynamics of the problem, which does not exists to date.The existing previous research activities on hover in ground effect mostly focused on parallel ground planes. The performance benefits and flow field characteristics associated with hover in ground effect over parallel ground planes are relatively well known. However, only a very limited amount of work has been done on non-parallel ground planes and the associated changes of the flow field. Numerical simulations (CFD) will be performed to investigate the effects of non-parallel ground planes on the rotor inflow and flowfield. This will significantly expand the knowledge in rotorcraft aerodynamics from a flow physical as well as from a modeling perspective.The goal of the proposed research is to investigate the fluid mechanics of a hovering rotor over non-parallel ground planes by means of finite-volume computational fluid dynamics. The specific objectives of the proposed work are:1) to analyze the required computational grid and rotor resolution needed to accurately capture the effects of non-parallel ground planes on the inflow distribution2) to assess the performace of different turbulence models3) to characterize the fluid dynamics and fundamental behavior of the rotor wake in non-parallel ground effect4) to validate the simulations by experimental data5) to extract characteristic dynamic inflow data, which can later on serve to validate existing or develop new inflow models

Impressum, Conny Wendler