WATER DROPLET IMPINGEMENT PREDICTION FOR ENGINE INLETS BY TRAJECTORY ANALYSIS IN A POTENTIAL FLOW FIELD

The present study aims to investigate the optimized profile of the body through minimizing the Drag coefficient in certain Reynolds regime. For this purpose, effective aerodynamic computations are required to find the Drag coefficient. Then, the computations should be coupled thorough an optimization process to obtain the optimized profile. The aerodynamic computations include calculating the surrounding potential flow field of an object, calculating the laminar and turbulent boundary layer close to the object, and calculating the Drag coefficient of the object’s body surface. To optimize the profile, indirect methods are used to calculate the potential flow since the object profile is initially amorphous. In addition to the indirect methods, the present study has also used axial singularity method which is more precise and efficient compared to other methods. In this method, the body profile is not optimized directly. Instead, a sink-and-source singularity distribution is used on the axis to model the body profile and calculate the relevant viscose flow field.

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Water droplet impingement on airfoils and aircraft engine inlets foricing analysis

Journal of Aircraft ◽

10.2514/3.46008 ◽

1991 ◽

Vol 28 (3) ◽

pp. 165-174 ◽

Cited By ~ 4

Author(s):

Michael Papadakis ◽

R. Elangovan ◽

George A. Freund ◽

Marlin D. Breer

Keyword(s):

Water Droplet ◽

Aircraft Engine ◽

Droplet Impingement

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Three-dimensional hydrodynamics numerical of wind-driven circulations in Danjiangkou Reservoir

MATEC Web of Conferences ◽

10.1051/matecconf/201824602021 ◽

2018 ◽

Vol 246 ◽

pp. 02021

Author(s):

Jie Zhu ◽

Jin Quan ◽

Xiaohui Lei ◽

Xia Yue ◽

Yang Duan

Keyword(s):

Wind Speed ◽

Flow Field ◽

Potential Flow ◽

Flow Direction ◽

Three Dimensional ◽

Surface Flow ◽

Surface Velocity ◽

Wind Condition ◽

Reservoir Area ◽

Danjiangkou Reservoir

This paper focuses on the analysis of the flow field of Danjiangkou Reservoir under the action of wind stress. Based on the analysis of the annual wind field data of Danjiangkou Reservoir, the three-dimensional hydrodynamic model of Danjiangkou Reservoir was established. The distribution of water flow field in the reservoir area under five different wind directions and two different wind speeds was studied. The simulation results were compared with the flow field without wind. The results show that when the wind speed in the reservoir area is 3.3m/s, the surface velocity and flow direction change less under the same wind conditions as the potential flow direction. Under the wind condition opposite to the potential flow direction, the reservoir area is locally generated. The small circulation and surface flow are more disordered; when the wind speed reaches 10.0m/s, under the same wind condition as the potential flow direction, the surface velocity of the reservoir area increases significantly. Under the wind condition opposite to the direction of the potential flow, a stable counterclockwise circulation is generated, and the wind direction dominates the surface layer. seriously affecting the flow field distribution in the reservoir area. The research results in this paper can provide support for the reservoir in the formulation of emergency water pollution emergency strategy and the formulation of real-time scheduling plan.

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A Eulerian Method for Water Droplet Impingement by Means of an Immersed Boundary Technique

Journal of Fluids Engineering ◽

10.1115/1.4025867 ◽

2014 ◽

Vol 136 (4) ◽

Cited By ~ 7

Author(s):

Francesco Capizzano ◽

Emiliano Iuliano

Keyword(s):

Water Droplet ◽

Numerical Solutions ◽

Experimental Testing ◽

Three Dimensional ◽

Immersed Boundary ◽

Test Cases ◽

Ice Accretion ◽

Droplet Impingement ◽

Protection Systems ◽

Numerical Approaches

The estimation of water droplet impingement is the first step toward a complete ice accretion assessment. Numerical approaches are usually implied to support the experimental testing and to provide fast responses when designing ice protection systems. Basically, two different numerical methodologies can be found in literature: Lagrangian and Eulerian. The present paper describes the design and development of a tool based on a Eulerian equation set solved on Cartesian meshes by using an immersed boundary (IB) technique. The tool aims at computing the evolution of a droplet cloud and the impingement characteristics onto the exposed surfaces of an aircraft. The robustness of the methodology and the accuracy of the approach are discussed. The method is applying to classical two- and three-dimensional test cases for which experimental data are available in literature. The results are compared with both experiments and body-fitted numerical solutions.

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Domain Optimization Analysis of Potential Flow Field.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B ◽

10.1299/kikaib.61.103 ◽

1995 ◽

Vol 61 (581) ◽

pp. 103-108 ◽

Cited By ~ 8

Author(s):

Eiji Katamine ◽

Hideyuki Azegami

Keyword(s):

Flow Field ◽

Potential Flow ◽

Optimization Analysis ◽

Domain Optimization

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A solution for potential flow over an arc fiber

Thermal Science ◽

10.2298/tsci1205564w ◽

2012 ◽

Vol 16 (5) ◽

pp. 1564-1568 ◽

Cited By ~ 1

Author(s):

Wenxi Wang ◽

Qing He ◽

Nian Chen ◽

Yuan Zhou ◽

Mingliang Xie

Keyword(s):

Flow Field ◽

Potential Flow ◽

Orientation Angle ◽

Flow Fields ◽

Single Fiber ◽

Incoming Flow ◽

Geometric Properties ◽

Stream Functions

In the paper, the flow field around an arc fiber is studied. Based on the Zhukovsky conversion, the potential and stream functions are derived. The results show that the flow fields depend on geometric properties of the arc fiber and the orientation angle of the incoming flow. The flow field developed in this paper can be used to predict the single-fiber efficiency for the arc fiber.

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On the Propagation of Viscous Wakes and Potential Flow in Axial-Turbine Cascades

Journal of Turbomachinery ◽

10.1115/1.2929196 ◽

1993 ◽

Vol 115 (1) ◽

pp. 118-127 ◽

Cited By ~ 25

Author(s):

T. Korakianitis

Keyword(s):

Flow Field ◽

Potential Flow ◽

Leading Edge ◽

Local Pressure ◽

Flow Disturbance ◽

Unsteady Forces ◽

Flow Interaction ◽

Wake Interaction ◽

Pitch Ratio ◽

Relative Flow

This paper investigates the propagation of pressure disturbances due to potential-flow interaction and viscous-wake interaction from upstream blade rows in axial-turbine-blade rotor cascades. Results are obtained by modeling the effects of the upstream stator viscous wake and potential-flow fields as incoming disturbances on the downstream rotor flow field, where the computations are performed. A computer program is used to calculate the unsteady rotor flow fields. The amplitudes for the rotor inlet distortions due to the two types of interaction are based on a review of available experimental and computational data. We study the propagation of the isolated potential-flow interaction (no viscous-wake interaction), of the isolated viscous wake interaction (no potential-flow interaction), and of the combination of interactions. The discussion uses as example a lightly loaded cascade for a stator-to-rotor-pitch ratio R = 2. We examine the relative magnitudes of the unsteady forces for two different stator-exit angles. We also explain the expected differences when the stator-to-rotor pitch ratio is decreased (to R = 1) and increased (to R = 4). We offer new and previously unpublished explanations of the mechanisms of generation of unsteady forces on the rotor blades. The potential flow field of the rotor cuts into the potential flow field of the stator. After the potential-flow disturbance from the stator is cut into a rotor cascade, it propagates into the relative flow field of the rotor passage as a potential-flow disturbance superimposed on the rotor-relative flow. The potential flow field of the rotor near the leading edge and the leading edge itself cut into the wake and generate two counterrotating vortical patterns flanking the wake centerline in the passage. The vortical pattern upstream of the wake centerline generates an increase in the local pressure (and in the forces acting on the sides of the passage). The vortical pattern downstream of the wake centerline generates a decrease in the local pressure (and in the forces acting on the sides of the passage). The resulting unsteady forces on the blades are generated by the combined (additive) interaction of the two disturbances.

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