Numerical Simulation of Unsteady Conjugate Heat Transfer of Electrothermal Deicing Process

Abstract

A novel 3-D unsteady model of in-flight electrothermal deicing process is presented in this paper to simulate the conjugate mass and heat transfer phenomena of water film runback, phase change, and solid heat conduction. Mathematical models of water film runback and phase change are established and solved by means of a loosely coupled method. At the current time step, solid heat conduction, water film runback, and phase change are iteratively solved until the heat boundary condition reaches convergence, then the temperature distribution and ice shape at the moment are obtained, and the calculation of the next time step begins subsequently. A deicing process is numerically simulated using the present model following an icing tunnel experiment, and the results match well with those in the literatures, which validate the present model. Then, an in-flight deicing process is numerically studied to analyze the effect of heating sequence.

Unsteady simulation of aircraft electro-thermal deicing process with temperature-based method

“…The unsteady results matched well with those of the FENSAP-ICE software, but the unsteady deicing model was not explicitly given. Mu 22 established a 3D unsteady model for the thermal deicing simulation, and the results showed agreement with the literature data. However, the effects of the existing ice layer were not tightly coupled in the runback water thermodynamics either.…”

Numerical simulation of aircraft thermal anti-icing system based on a tight-coupling method

“…In the equations above, the impinging water flow rate imp m & can be obtained by the following equation [24]:…”

“…Therefore, the external air flow is usually decoupled from the conjugate heat transfer solution of the anti-icing system in traditional loose-coupling methods. To stand for the external airflow heat transfer characteristics, the convective heat transfer coefficient is obtained by boundary layer integration methods [23] or CFD methods [24] under isothermal wall boundary conditions, and would not be updated during the coupling iteration of the solid heat conduction and the runback water thermodynamics [22]. However, Morency [25] found that a sharp rise occurred in the convective heat transfer coefficient when non-isothermal temperature increased, and this phenomenon was not captured using constant isothermal surface.…”

Pitot Tube-Based Icing Detection: Effect of Ice Blocking on Pressure

“…Therefore, only the trend of temperature change is shown. In the process of forming glaze ice, the temperature of the water droplets increases slightly due to the solidification of the water droplets such that the gas temperature at the front part of the pitot tube rises to the highest point T1 [14], and the total pressure hole is partially blocked. However, as ice accumulates and becomes increasingly thick, the heat released by solidification is not transmitted to the front end of the pitot tube and is dissipated by airflow.…”