Thermally Induced Flow Structures in Aircraft Wing Compartments

2008 ◽  
Author(s):  
D. Newport ◽  
V. Egan ◽  
M. Aguanno ◽  
V. Lacarac ◽  
B. Estebe ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Composite Material ◽  
Composite Materials ◽  
Thermal Environment ◽  
Flow Structures ◽  
Heat Transfer Mechanism ◽  
Commercial Aircraft ◽  
Aircraft Wing ◽  
Thermally Induced ◽  
Induced Flow

The use of composite material in modern commercial aircraft has increased significantly in recent years. The very low conductivity relative to Aluminium of composite materials means that the thermal environment experienced in an aircraft, during flight and on the apron, are significantly altered. The heat transfer mechanism is complex: natural and mixed convection flows established in compartments. This paper presents the thermally induced flow structures under representative conditions for a rectangular cavity representative of wing boxes and horizontal tail planes. The paper highlights the sensitivity to boundary conditions, the effect of structural stiffeners. The results indicate it may be possible to incorporate the effect of stringers and heating from above into existing correlations.

scholarly journals Development of Detailed FE Numerical Models for Assessing the Replacement of Metal with Composite Materials Applied to an Executive Aircraft Wing

Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 178
Author(s):  
Valerio Acanfora ◽  
Roberto Petillo ◽  
Salvatore Incognito ◽  
Gerardo Mario Mirra ◽  
Aniello Riccio
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Numerical Model ◽  
Numerical Models ◽  
Structural Performance ◽  
Aircraft Wing ◽  
Resin Infusion ◽  
Effectiveness Analysis ◽  
Liquid Resin Infusion ◽  
Process Constraints

This work provides a feasibility and effectiveness analysis, through numerical investigation, of metal replacement of primary components with composite material for an executive aircraft wing. In particular, benefits and disadvantages of replacing metal, usually adopted to manufacture this structural component, with composite material are explored. To accomplish this task, a detailed FEM numerical model of the composite aircraft wing was deployed by taking into account process constraints related to Liquid Resin Infusion, which was selected as the preferred manufacturing technique to fabricate the wing. We obtained a geometric and material layup definition for the CFRP components of the wing, which demonstrated that the replacement of the metal elements with composite materials did not affect the structural performance and can guarantee a substantial advantage for the structure in terms of weight reduction when compared to the equivalent metallic configuration, even for existing executive wing configurations.

Measurement of Heat Transfer and Flow Structures in a Closed Rotating Cavity

2022 ◽  
Author(s):  
Richard Jackson ◽  
Hui Tang ◽  
James Scobie ◽  
J. Michael Owen ◽  
Gary Lock
Keyword(s):  
Heat Transfer ◽  
Gas Turbines ◽  
Pressure Sensors ◽  
Flow Structures ◽  
Closed Cavity ◽  
Experimental Range ◽  
Wide Range ◽  
Industrial Gas Turbines ◽  
Induced Flow ◽  
Compressibility Effects

Abstract Buoyancy-induced flow occurs inside the rotating compressor cavities of gas turbines. These cavities are usually open at the inner radius, but in some industrial gas turbines, they are effectively closed. This paper presents measurements of the disc heat transfer and rotating flow structures in a closed cavity over a wide range of engine relevant conditions. These experimentally derived distributions of disc temperature and heat flux are the first of their kind to be published. The radial distribution of the non-dimensional disc temperature virtually collapsed onto a single curve over the full experimental range. There was a small, monotonic departure from this common curve with increasing Reynolds number; this was attributed to compressibility effects where the core temperature increases as the rotational speed increases. These results imply that, if compressibility effects are negligible, all rotating closed cavities should have a disc temperature distribution uniquely related to the geometry and disc material; this is of important practical use to the engine designer. Unsteady pressure sensors detected either three or four vortex pairs across the experimental range. The number of pairs changed with Grashof number, and the structures slipped relative to the rotating discs by less than 1% of the disc speed.

An Approach to Enhancement of Conductivity in Composite Material Using Nanotechnology

2006 ◽  
Author(s):  
Vivian T. Dang ◽  
Russ Maguire ◽  
Robab Safa-Bakhsh
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Composite Structure ◽  
Composite Structures ◽  
Test Methods ◽  
Commercial Aircraft ◽  
Nano Technology ◽  
Novel Approaches ◽  
Non Destructive ◽  
Potential Integration

This review documents possible developments using Nano technology to enhance electromagnetic effects (EME) and identifies the potential integration on the composite structures for the next generation composite commercial aircraft. First, developments using Nano technology as a source to enhance the EME of the composite will be discussed. These developments include computational modeling of Nano-filled composites to predict certain properties and behaviors of Nano-enhanced materials, test methods for non-destructive examination of Nano-modified materials, and other novel approaches to resolve the challenges of increasing conductivity in composite materials. Next, the details of the potential impacts of using Nano technology for increasing conductivity will be outlined. Finally, the implementation of a Nano-enhanced material on the composite structure will be described.

scholarly journals Experimental research on effect of opening configuration and reinforcement method on buckling and strength analyses of spar web made of composite material

2021 ◽  
Vol 28 (1) ◽  
pp. 190-203
Author(s):  
Lin Sen ◽  
Li Chenxi ◽  
Hu Ying ◽  
Cong Hao
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Experimental Research ◽  
Commercial Aircraft ◽  
Strength Performance ◽  
Structural Reinforcement ◽  
Web Structure ◽  
Buckling Stability ◽  
Reinforcement Efficiency

Abstract This study experimentally investigates the effect of the opening configuration on the buckling stability and bearing performance of a structural beam web used in a commercial aircraft made of composite materials. The buckling and strength analyses on three opening configurations (circular, oblong, and rhombic) were carried out using test samples with identical web surface size. It is found that the rhombic opening has the minimum effect on the buckling stability and strength of the structure. To compensate for the effect of the opening, two reinforcement methods, using reinforcement rib and thickening the sample, were also investigated in this study. It is concluded that thickening the sample can more effectively improve the buckling stability and strength performance of beam web structure and hence has relatively higher structural reinforcement efficiency.

Measurement of Heat Transfer and Flow Structures in a Closed Rotating Cavity

2021 ◽  
Author(s):  
Richard W. Jackson ◽  
Hui Tang ◽  
James A. Scobie ◽  
J. Michael Owen ◽  
Gary D. Lock
Keyword(s):  
Heat Transfer ◽  
Gas Turbines ◽  
Pressure Sensors ◽  
Flow Structures ◽  
Closed Cavity ◽  
Experimental Range ◽  
Wide Range ◽  
Industrial Gas Turbines ◽  
Induced Flow ◽  
Compressibility Effects

Abstract Buoyancy-induced flow occurs inside the rotating compressor cavities of gas turbines. These cavities are usually open at the inner radius, but in some industrial gas turbines, they are effectively closed. This paper presents measurements of the disc heat transfer and rotating flow structures in a closed cavity over a wide range of engine relevant conditions. These experimentally derived distributions of disc temperature and heat flux are the first of their kind to be published. The radial distribution of the non-dimensional disc temperature virtually collapsed onto a single curve over the full experimental range. There was a small, monotonic departure from this common curve with increasing Reynolds number; this was attributed to compressibility effects where the core temperature increases as the rotational speed increases. These results imply that, if compressibility effects are negligible, all rotating closed cavities should have a disc temperature distribution uniquely related to the geometry and disc material; this is of important practical use to the engine designer. Unsteady pressure sensors detected either three or four vortex pairs across the experimental range. The number of pairs changed with Grashof number, and the structures slipped relative to the rotating discs by less than 1% of the disc speed.

Measurement of Transient Natural Convection in Non-Ventilated Aircraft Compartments

2008 ◽  
Author(s):  
V. Egan ◽  
T. W. Confrey ◽  
D. Newport ◽  
V. Lacarac
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Temperature Distribution ◽  
Secondary Flows ◽  
Flow Structures ◽  
Flow Visualisation ◽  
Transient Effects ◽  
Aircraft Wing ◽  
Full Field ◽  
Side Walls

The present study focuses on heat transfer behaviour in aircraft compartments. The objectives of the analysis were to investigate the transient effects on fluid flow structures and heat transfer mechanisms in aircraft wing boxes relative to aircraft turnaround times. Experimental methods employed were flow visualisation and thermocouple measurements. A simplified air filled aluminium rectangular enclosure of aspect ratio 0.25 was constructed to replicate an aircraft wing box. Rubber insulation was used between wall surfaces to maintain separate thermal boundary conditions at each wall. Flow visualisation was used to illustrate the transient evolution of full field flow structures and thermocouple measurements were recorded to investigate the full field transient temperature distribution. Experiments were carried out from time zero to steady state and were conducted for Rayleigh numbers of 2.87×106, 4.81×106 and 7.39×106 based on enclosure height. Fluid flow patterns revealed the presence of two counter acting flows in the cavity with a downward motion adjacent to the front and rear sides of the enclosure. The downward motions were present due to the cooling of the warm air inside the cavity by the adjacent cooler aluminium side walls. Secondary flows existed in the lower region of the cavity specifically prominent to the front and rear surfaces where the height of detachment of the flow varied with time and temperature of the adjacent side walls. Transient spatial temperature distribution plots confirmed the approach to steady state was gradual, that a vertically thermal stratified distribution existed in the cavity and the presence of the thermal boundary layers along the horizontal and vertical walls were clearly evident. It was concluded that transient effects are significant relative to aircraft turnaround times as it was observed that the flow structures change over the initial transient phase of analysis and remain similar thereafter. Wing box material thermophysical properties influenced the developed flow structures causing two secondary flows to exist along the front and rear spar walls. Vertical temperature distribution results were generalised using a power law based on dimensionless time (t*), dimensionless temperature (T*) and Rayleigh number.

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