ICICLE: A Model for Glaciated & amp; Mixed Phase Icing for Application to Aircraft Engines

Abstract

High altitude ice crystals can pose a threat to aircraft engine compression and combustion systems. Cases of engine damage, surge and rollback have been recorded in recent years, believed due to ice crystals partially melting and accreting on static surfaces (stators, endwalls and ducting). The increased awareness and understanding of this phenomenon has resulted in the extension of icing certification requirements to include glaciated and mixed phase conditions. Developing semi-empirical models is a cost effective way of enabling certification, and providing simple design rules for next generation engines. A comprehensive ice crystal icing model is presented in this paper, the Ice Crystal Icing ComputationaL Environment (ICICLE). It is modular in design, comprising a baseline code consisting of an axisymmetric or 2D planar flowfield solution, Lagrangian particle tracking, air-particle heat transfer and phase change, and surface interactions (bouncing, fragmentation, sticking). In addition, an efficient particle tracking method has been developed into the code, which employs the representative particle size distribution at each injection location and a deterministic particle sticking method by using an in-situ particle based scaling factor without aborting the particle trajectories. Various time integration algorithms, including implicit and explicit Euler and Runge-Kutta methods, are discussed and the effect on an acceptable timestep investigated. The model then improves on those available in the literature in three ways: firstly, an adaptation of the Extended Messinger Model (EMM) to mixed phase conditions is incorporated, improving the fidelity of the ice accretion prediction compared with the classical Messinger model. Secondly, an experimentally-derived model for sticking efficiency improves the accuracy of the continuity equation in the EMM; thirdly a simple model for integrating two-way coupling of mass and energy is proposed.

A Three-Layer Thermodynamic Model for Ice Crystal Accretion on Warm Surfaces: EMM-C

“…This code features Lagrangian particle tracking and phase change, semi-empirical sticking and erosion models and the EMM-C model. Further detail and more results of model validation -may be found in [20].…”

Sticking–Erosion Model for Ice Crystal Icing Using Particle Size Distribution

“…The present study aims 1) to develop a sticking-erosion model at individual particle-scale and 2) to improve the understanding in the contribution of particle size on ICI. Modelling ICI is carried out using the in-house icing code, ICICLE [10]…”

“…Due to the threat, new certification requirements have been introduced by FAA in Amendment 34 of 14 CFR 33 and by EASA in Amendment 4 of CS-E and Amendment 16 of CS-25. Several ice crystal icing codes have been developed to support the design and certification of engines/aircrafts, including GlennICE from NASA [4], IGLOO2D from ONERA [5,6], FENSAP-ICE by Habashi et al [7], MooseMBIce extended by Norde et al [8,9], as well as ICICLE at Oxford [10,11]. Understanding the sticking and erosion behaviours of ice crystals is an important element to develop a mathematical model of the phenomenon to introduce in icing codes.…”

A Review on the Current Status of Icing Physics and Mitigation in Aviation

“…(2) Numerical Models of Ice Crystal Icing Physics In addition to researchers' efforts to determine essential factors in icing conditions such as TWC, numerical simulations to predict two-dimensional ice accretion due to ice crystal icing have been developed (GlennIce from NASA [89], IGLOO2D from ONERA [90], FENSAP-ICE from ANSYS [91], and ICICLE from University of Oxford [92]). The primary strategy in the development of ice crystal icing simulations is to introduce the unique features of ice crystal icing into conventional icing simulations of a supercooled water droplet.…”