Transferência de calor e massa no escoamento bifásico em torno de aerofólios equipados com sistemas de antigelo aeronáuticos.

Silva, Guilherme Araújo Lima da

doi:10.11606/t.3.2009.tde-27032009-082825

Cited by 6 publications

(2 citation statements)

References 29 publications

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“…Makkonen uses a similar assumption to calculate the momentum boundary layer thickness at the transition point, but he considers that the laminar momentum thickness δ 2,o is summed in the Equation 11, that leads to the Equation 13. …”

Section: Laminar-turbulent Transition Regionmentioning

confidence: 99%

Heat Transfer on Iced Cylinders

Stefanini

Silvares

Silva³

et al. 2010

AIAA Atmospheric and Space Environments Conference

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The convective heat transfer is the main mechanism to remove the solidification enthalpy during glaze ice accretion. Most of the airfoil icing prediction codes use a heat transfer calculation procedure based on the classical integral evaluation of the boundary layer. These icing codes consider a smooth surface in laminar regime, the fully rough surface in turbulent regime and that laminar-turbulent transition occurs abruptly without a transition region. This work presents the classical integral evaluation of the boundary layer and proposes the use of an intermittency function to represent the laminar-turbulent region. The present model is used to calculate the local heat transfer coefficient for a rough cylinder and the results are compared with experimental data and with numerical simulations of other authors. The discrepancies between the present results and the experimental data are analyzed and it is shown that an adequate calculation of the convective heat transfer requires that both equivalent sand grain roughness height and rough Stanton number shall represent the characteristics of the rough surface and it is desirable that they are determined experimentally to each type of surface.

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Section: Laminar-turbulent Transition Regionmentioning

confidence: 99%

Heat Transfer on Iced Cylinders

Stefanini

Silvares

Silva³

et al. 2010

AIAA Atmospheric and Space Environments Conference

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“…One of the present authors implemented the Abu-Ghannam & Shaw transition and intermittency models 26 into BLP2C code in his Ph.D. thesis development. 4 Its results were compared with experimental data and other numerical results of integral analysis with linear combination models and finite volume differential analysis (CFD commercial code) with intermittency transport equations. 41…”

Section: Laminar-turbulent Transition Modelingmentioning

confidence: 99%

Differential Boundary-Layer Analysis and Runback Water Flow Model Applied to Flow Around Airfoils with Thermal Anti-ice

Araujo

Jorge

Jesus

et al. 2009

1st AIAA Atmospheric and Space Environments Conference

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Certification regulations require safe flight under icing conditions, therefore, ice protection on aircraft wings and horizontal stabilizers will be necessary if critical aerodynamic performance degradation is to be avoided. The present paper developed a numerical code for prediction of heat and mass transfer in two-phase flow around aeronautical airfoils. These systems are equipped with thermal anti-ice systems that are designed to keep the surface free of ice as much as possible. The code is able to estimate the temperatures and runback water around the airfoil surface due implementation of heat transfer submodels in a baseline thermal anti-ice model: 1) it estimated the airfoil surface wetness factor by means of a runback water film and rivulets pattern flow models; 2) it evaluated the laminar and turbulent boundary layers with pressure gradient and laminar-turbulent transition over non-isothermal and permeable airfoil surfaces by performing integral and differential boundary layer analysis; and 3) it predicted the onset position and length of the laminarturbulent transition region with pressure gradient and turbulence level effects. The work followed a validation and verification process during the numerical code development. All submodels results were separately verified against experimental data. The numerical results of the thermal performance of the airfoil with the anti-ice baseline model, plus the present contributions, were validated against experimental data of an electrically heated NACA 0012 airfoil operating in the Icing Reseach Tunnel (IRT), NASA, USA. Nomenclature A= finite volume area exposed to flow around the airfoil, m 2 B h = heat transfer driving force B m = mass transfer driving force h = convective heat transfer coefficient,W/(m 2 · K) c p = specific heat, J/(kg · K) E = mechanical energy, J e = mechanical energy per unit of film width, J/m F = wetness factor F r = rivulets flow wetness factor F s = stream wise wetness factor G = mass flux ρ · u e , kg/(s · m 2 ) g(θ 0 ) = auxiliary function, −1/4 cos 3 θ 0 − 13/8 cos θ 0 + 15θ 0 /8 sin θ 0 − 3/2θ 0 sin θ 0 g m = mass transfer conductance, kg/(s · m 2 ) h = convection heat transfer coefficient, W/(m 2 · K) h = water film height at film break-up position, m h + = non-dimensional critical film height at film break-up position, (ρτ 2 h 3 0 )/(6µ 2 σ f g ) h 0 = critical film height at break-up position, m h r = rivulet height downstream break-up position, m h(x) = half rivulet height in function of its horizontal coordinate,R(cos θ − cosθ 0 ), m i = specific enthalpy, J/kg k = thermal conductivity, W/(m · K) m = mas flow rate, kg/s Ma = Mach number p = pressure, Pa p mixt = total mixture pressure, Pa p vap = partial vapor pressure, Pȧ q = heat flux, W/m 2 q lost = heat transfer rate lost to gaseous flow, W R = rivulets radius, m r = high speed aerodynamic recovery factor R m = mean rivulet radius within the finite volume, 1/2 · (R out + R in ), m R t = thermal resistance, K/W s = stream wise distance over airfoil surface, m St = Stanton numb...

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Numerical Simulation of Coupled Heat and Mass Transfer for Airfoil Ice Protection Systems

Silva¹,

Barros²,

Rafael³

et al. 2023

Handbook of Numerical Simulation of in-Flight Icing

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Transferência de calor e massa no escoamento bifásico em torno de aerofólios equipados com sistemas de antigelo aeronáuticos.

Abstract: C.4 Re δ1 no ponto de indiferença em função do fator de gradiente de pressão Λ = (δ 2 /ν)(dU e /dx) (SCHLICHTING; GERSTEN, 2000). .. .. . C.5 Curvas de estabilidade neutra para várias temperaturas de parede T w

Cited by 6 publications

References 29 publications

Heat Transfer on Iced Cylinders

Heat Transfer on Iced Cylinders

Differential Boundary-Layer Analysis and Runback Water Flow Model Applied to Flow Around Airfoils with Thermal Anti-ice

Numerical Simulation of Coupled Heat and Mass Transfer for Airfoil Ice Protection Systems

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