Calculation of Flow Over Iced Airfoils

Cebeci, Tuncer

doi:10.2514/3.59908

Cited by 31 publications

(11 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The airflow computation could be from a Navier-Stokes solver, or a coupled inviscid flow solver with an integral boundary layer correction. Although the inviscid solver could be based on solution to the Euler equations, it is more likely to tackle potential flow using either panel methods ( [30], [31]) or finite-difference methods [32]. The water droplet trajectories and collection efficiency calculations are detailed in [3] while the ice-prediction typically follows from the energy-balance approach of [34], involving kinetic heating, convective cooling, latent heat of freezing and several sensible heat terms.…”

Section: Specific Icing Modelsmentioning

confidence: 99%

Ice formation on a smooth or rough cold surface due to the impact of a supercooled water droplet

Elliott

Smith²

2015

J Eng Math

View full text Add to dashboard Cite

Ice accretion is considered in the impact of a supercooled water droplet on a smooth or rough solid surface, the roughness accounting for earlier icing. In this theoretical investigation the emphasis and novelty lie in the full nonlinear interplay of the droplet motion and the growth of the ice surface being addressed for relatively small times, over a realistic range of Reynolds numbers, Froude numbers, Weber numbers, Stefan numbers and capillary underheating parameters. The Prandtl number and the kinetic under-heating parameter are taken to be order unity. The ice accretion brings inner layers into play forcibly, affecting the outer flow. (The work includes viscous effects in an isothermal impact without phase change, as a special case, and the differences between impact with and without freezing.) There are four main findings. First, the icing dynamically can accelerate or decelerate the spreading of the droplet whereas roughness on its own tends to decelerate spreading. The interaction between the two and the implications for successive freezings are found to be subtle. Second, a focus on the dominant physical effects reveals a multi-structure within which restricted regions of turbulence are implied. The third main finding is an essentially parabolic shape for a single droplet freezing under certain conditions. Fourth is a connection with a body of experimental and engineering work and with practical findings to the extent that the explicit predictions here for ice-accretion rates are found to agree with the experimental range.

show abstract

Section: Specific Icing Modelsmentioning

confidence: 99%

Ice formation on a smooth or rough cold surface due to the impact of a supercooled water droplet

Elliott

Smith²

2015

J Eng Math

View full text Add to dashboard Cite

show abstract

“…The thermal wall function used in OF1.6-ext is given by Eqs. (17) and (15) and same momentum wall function of Fig. 1(b).…”

Section: Resultsmentioning

confidence: 94%

“…The present authors coded the Eqs. (15) and 17into the OF source code in order to modify the wall function called alphatRoughWallFunction.…”

Section: Wall Functions Models Descriptionmentioning

confidence: 99%

“…Differential analyses application to aircraft icing problems momentum are not so common as the integral form. The results of California State University Long Beach group have been validated in predicting momentum and heat transfer around icing airfoils [15,16,17]. These works also used the Nikurases's concept of equivalent sand grain roughness height K s in the eddy viscosity formulation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Proposed Wall Function Models for Heat Transfer around a Cylinder with Rough Surface in Cross Flow

Silva¹,

Arima²,

Branco

et al. 2011

SAE Technical Paper Series

View full text Add to dashboard Cite

This paper proposes wall function models to simulate the heat transfer around a cylinder in cross flow with an isothermal and rough surface. The selected case has similitudes with aircraft wing icing: the ice roughness shape, height and distribution. Moreover, the flow is somewhat similar to that found on iced airfoil; and the surface is isothermal like when icing. The Reynolds-Averaged Navier-Stokes, turbulence, energy and mass conservation 7-equation system is solved by two Computational Fluid Dynamics (CFD) codes. To represent accurately the effects of roughness on the heat transfer, the present authors had to modify both codes and to propose new thermal wall functions for them. In addition, it was implemented a momentum wall function that is not so common in CFD codes but it is a standard in aircraft icing simulation. Basically, the present paper is focused on presenting the simulation results improvement obtained by the implementation of thermal wall functions that also considered the effect thermal resistance of viscous sub-layer on convective heat transfer. The numerical results were compared to experimental data of heat transfer around cylinders with an isothermally heated surface and equivalent sand grain roughness height of K s /D = 900 • 10 −5. For the selected case, the flow regime was trans-critical at Reynolds numbers Re = u e • D/ν = 2.2 • 10 5. Due to significant blockage effects present in the experimental data, the tunnel walls were also meshed and simulated. In sum, the implementation into CFD codes was considered adequate because the results were close to experimental data around the whole cylinder surface, not only along the leading edge or the separated region. The results accuracy were improved when compared with CFD factory original models. However, the results indicate that further works on wall functions and their validation are required before using CFD in wing aircraft icing.

show abstract

“…Para a validação dos resultados, o autor utilizou os dados experimentais de Achenbach (1977), que mediu a transferência de calor ao redor de cilindros com superfícies rugosas e em vários regimes de escoamento. Cebeci (1987Cebeci ( , 1989 aplicou seu próprio código de camada limite por diferenças finitas (CEBECI, 1971) Uma comparação do atrito e da previsão de transferência de calor com vários modelos de rugosidade e com dados experimentais foi apresentado por Havugimana et al (2002), que resolveu o escoamento por diferenças finitas com um modelo de turbulência de comprimento de mistura de Cebeci-Smith modificado. O autor considerou o conceito de rugosidade equivalente do grão de areia e o modelo de rugosidade de elementos discretos.…”

Section: Referências Básicasunclassified

Efeitos da camada limite térmica na formação de gelo em aerofólios de uso aeronáutico.

Stefanini¹

View full text Add to dashboard Cite

O modelo de avaliação da camada limite dinâmica e térmica foi implementado, no presente trabalho, em um código numérico para o cálculo do coeficiente de transferência de calor convectivo sobre aerofólios de uso aeronáutico com formação de gelo. Foram considerados, no modelo da camada limite turbulenta, os efeitos da rugosidade equivalente do grão de areia k s , e transição entre o regime laminar e turbulento foi avaliada por dois modelos, um abrupto e um suave. Para a transição suave foi utilizada uma função intermitência proposta por (ABU-GHANNAM; SHAW, 1980). O código desenvolvido neste trabalho foi acoplado aos módulos do código ONERA com o objetivo de simular as formas de gelo em aerofólios para diversas condições de escoamento do ar com conteúdo deágua. As formas de gelo obtidas foram comparadas com dados experimentais de Shin e Bond (1994) e com resultados de simulações dos códigos LEWICE, TRAJICE e ONERA (KIND, 2001). Os resultados das simulações do presente trabalho apresentaram boa semelhança com os resultados dos outros códigos. A simulação da previsão de formas de gelo do tipo Glaze, do presente trabalho e dos outros códigos, resultou em formas de gelo de espessura e volume menores que as formas experimentais. Foi verificado que uma previsão adequada do coeficiente de transferência de calor convectivo afeta a simulação das formas deste tipo de gelo. Um caso de Kind (2001) foi utilizado para avaliar os efeitos dos parâmetros da camada limite dinâmica e térmica na formação de gelo em aerofólios. Verificou-se que a posição do início da transição do regime laminar para o turbulento, o comprimento da transição e o valor da rugosidade afetam a forma, a espessura e o volume do gelo, e que estes parâmetros podem ser utilizados para ajustes dos modelos de camada limite para melhores previsões de formas de gelo do tipo Glaze.

show abstract

Calculation of Flow Over Iced Airfoils

Cited by 31 publications

References 10 publications

Ice formation on a smooth or rough cold surface due to the impact of a supercooled water droplet

Ice formation on a smooth or rough cold surface due to the impact of a supercooled water droplet

Proposed Wall Function Models for Heat Transfer around a Cylinder with Rough Surface in Cross Flow

Efeitos da camada limite térmica na formação de gelo em aerofólios de uso aeronáutico.

Contact Info

Product

Resources

About