Numerical simulation of hot-air piccolo tubes for icing protection systems

Abstract

© Springer Nature Switzerland AG 2024. All rights reserved.In-flight ice protection is typically performed by mechanical, chemical, thermal, or hybrid systems. One of the most traditional, cost-effective, and still often used techniques is hot-air anti-icing, which normally heats the interior of the affected aerodynamic surfaces with an array of small hot-air jets generated by a perforated tube (piccolo). These devices are designed to optimally distribute the energy along the protected area, ensuring that the local heat demand for anti-icing can be satisfactorily achieved. In this chapter, an example of a low-cost numerical model to resolve the compressible internal flow along the length of a piccolo is provided. The governing equations are those of the thermodynamic state of air, mass continuity, momentum, and energy conservation. The equations are used in algebraic form and are solved in sequential control volumes that are axially distributed along with the piccolo. At each orifice of the piccolo, the airflow is also treated in one dimension, with the intrinsic three-dimensionality of the air efflux being modeled with the help of a discharge coefficient correlation. A correlation can be based on experimental data, which is the case in the comparisons to the experimental results presented later in this chapter. This technique is quite efficient since it allows the prediction of the flow distribution along with a piccolo without demanding a high computational effort. As a direct benefit, for instance, the use of such low-cost models allows the analysis of multiple piccolo configurations before the selection of one for laboratory testing or production.

Keywords