Review on ducted fans for compound rotorcraft

ABSTRACTThis paper presents a survey of published works on ducted fans for aeronautical applications. Early and recent experiments on full- or model-scale ducted fans are reviewed. Theoretical studies, lower-order simulations and high-fidelity CFD simulations are also summarised. Test matrices of several experimental and numerical studies are compiled and discussed. The paper closes with a summary of challenges for future ducted fan research.

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High-fidelity CFD Simulations of Two Wind Turbines in Arrays using Nonlinear Frequency Domain Solution Method

Renewable Energy ◽

10.1016/j.renene.2021.04.067 ◽

2021 ◽

Author(s):

Shine Win Naung ◽

Mahdi Erfanian Nakhchi ◽

Mohammad Rahmati

Keyword(s):

Frequency Domain ◽

Wind Turbines ◽

Solution Method ◽

High Fidelity ◽

Nonlinear Frequency ◽

Cfd Simulations

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Full-scale self-propulsion simulation with a discretized propeller

TRANSACTIONS OF THE KRYLOV STATE RESEARCH CENTRE ◽

10.24937/2542-2324-2021-4-398-15-23 ◽

2021 ◽

Vol 4 (398) ◽

pp. 15-23

Author(s):

Zhang Qingshan ◽

◽

Chen Weimin ◽

Du Yunlong ◽

Dong Guoxiang ◽

...

Keyword(s):

Boundary Layer Thickness ◽

Polynomial Interpolation ◽

Flow Characteristics ◽

Uncertainty Assessment ◽

Full Scale ◽

The Self ◽

High Fidelity ◽

Cfd Simulations ◽

Towing Tank ◽

Grid Application

A comparison between towing tank testing and full-scale CFD simulations is presented at three different target speeds. For the current self-propulsion simulation, the self-propulsion point was obtained using polynomial interpolation. The studies of boundary layer thickness, a basic grid uncertainty assessment and verification were performed to give some confidence of grid application to current self-propulsion simulation. All simulations are performed using a commercial CFD software STAR-CCM+. It is concluded that with high-fidelity numerical methods, it’s possible to treat hull roughness and directly calculate full-scale flow characteristics, including the effects of the free surface, none-linearity, turbulence and the interaction between propeller, hull and the flow field.

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A study of the interaction of a travelling shock wave with a solid-propellant rocket motor head end

10.32920/ryerson.14653677 ◽

2021 ◽

Author(s):

Robert Elian Feteanu

Keyword(s):

Shock Wave ◽

Rocket Motor ◽

Combustion Chambers ◽

Cfd Simulations ◽

Radial Wave ◽

Flow Models ◽

Numerical Studies ◽

Solid Propellant Rocket ◽

Wave Development ◽

Solid Rocket

Experimental and numerical studies have been undertaken to examine various aspects pertaining to the interaction of an incident travelling shock wave with a solid rocket motor's head end (forward section), in order to identify any potential gasdynamic mechanism of wave reinforcement pertinent to combustion instability behaviour in these motors. A cold-flow experiment, based on a shock tube scheme tailored to the present application, has proved to be useful in providing information surrounding the interaction process. Both experimental and numerical results (CFD simulations) confirm the existence of substantial transient radial wave development superimposed on the base reflected axial shock wave. These results illustrate the potential weakness of one-dimensional flow models for certain engineering applications, where important multidimensional phenomena, such as those observed in this work, may not be captured. By analogy to actual propulsion system combustion chambers, the transverse wave activity is potentially a factor in supporting an augmentation of the local combustion rate in the head-end region of a rocket motor combustor.

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Dynamic Mode Decomposition Analysis of High-Fidelity CFD Simulations of the Sinus Ventilation

Flow Turbulence and Combustion ◽

10.1007/s10494-020-00156-8 ◽

2020 ◽

Vol 105 (3) ◽

pp. 699-713 ◽

Cited By ~ 2

Author(s):

Hadrien Calmet ◽

Daniel Pastrana ◽

Oriol Lehmkuhl ◽

Takahisa Yamamoto ◽

Yoshiki Kobayashi ◽

...

Keyword(s):

Decomposition Analysis ◽

Dynamic Mode Decomposition ◽

Dynamic Mode ◽

High Fidelity ◽

Cfd Simulations ◽

Mode Decomposition

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Validation of High-Fidelity CFD Simulations for Rocket Injector Design

44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit ◽

10.2514/6.2008-5226 ◽

2008 ◽

Cited By ~ 57

Author(s):

Paul Tucker ◽

Suresh Menon ◽

Charles Merkle ◽

Joseph Oefelein ◽

Vigor Yang

Keyword(s):

High Fidelity ◽

Cfd Simulations ◽

Injector Design

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An Assessment of the Validity of Quasi-Steady Analysis of Pressure Relief Valves

Volume 7: Fluids Engineering ◽

10.1115/imece2019-10607 ◽

2019 ◽

Author(s):

Christopher Doyle ◽

William Dempster ◽

Steven Taggart

Keyword(s):

Steady State ◽

High Fidelity ◽

Cfd Simulations ◽

Pressure Relief ◽

Ansys Fluent ◽

Interaction Processes ◽

Transient Simulations ◽

Flow Features ◽

Pressure Relief Valves ◽

Computational Fluid Dynamics Cfd

Abstract In this paper, the validity of the commonly used quasi-steady design approach to pressure relief valves (PRV) is examined by comparing detailed steady state conditions of valve behavior directly with transient conditions. To achieve this, a PRV conforming to ASME VIII standards was modelled using the commercial computational fluid dynamics (CFD) package ANSYS FLUENT to account for transient fluid-structure interaction processes. Detailed steady state CFD simulations were conducted using quasi-steady assumptions and compared to high fidelity transient moving mesh simulations to allow the piston forces to be examined. The results indicated that noticeably different magnitudes can occur between steady state and transient simulations; highlighting the possibility of significant differences occurring between quasi steady designed valves and their ultimate performance. In this paper, a single operating condition is examined, using air at 10.3 barg, for a 5231BX refrigeration valve supplied by the Henry Group to highlight the main issues. Analysis has indicated that the differences in performance are generated by temporal, short lived vortices at the piston surface which influences the bulk flow features as the disc accelerates and decelerates; altering the net disc forces when compared to steady state conditions.

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Hybrid RANS/LES Simulation of Combustor/Turbine Interactions

Volume 2B: Turbomachinery ◽

10.1115/gt2020-14873 ◽

2020 ◽

Author(s):

Guoping Xia ◽

Georgi Kalitzin ◽

Jin Lee ◽

Gorazd Medic ◽

Om Sharma

Keyword(s):

High Pressure ◽

Thermal Field ◽

Numerical Study ◽

High Fidelity ◽

Critical Aspect ◽

High Pressure Turbine ◽

Cfd Simulations ◽

Turbine Inlet ◽

Durability Design ◽

Turbine Vanes

Abstract Accurate prediction of thermal field in high pressure turbines is a critical aspect of aerodynamic and durability design. This is particularly true when the flow at turbine inlet exhibits large gradients in temperature, both radially and circumferentially. In other words, in the presence of hot streaks from the combustor. In the numerical study presented in this paper, coupled high-fidelity eddy-resolving simulations of a combustor and a turbine are used to study the differences in the temperature profile at the exit of the first vane and the heat flux on the first blade, resulting from different positioning, or clocking, between the combustor fuel nozzles and turbine vanes. The resolved unsteadiness and turbulence from the combustor impacts mixing and secondary flow in the high pressure turbine. Temperature profiles from both actual combustor CFD simulations, as well as and modulated profiles with more pronounced variation, or pattern factor, are used at the turbine inlet. A threshold of the pattern factor that brings the benefit of clocking is identified. Clocking positioning between the combustor and vanes was studied for the most benefit.

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