Introduction

What are we building?

This tutorial is designed as a workshop, where the user can navigate through a number of predefined experiments built around the orifice sizing flow balancing experiment contained within Modelon's Liquid Cooling Library (LCL). The model is a simplified representation of a thermal management system (TMS) onboard a hybrid-electric aircraft. Step-by-step info can be followed to gain an understanding of how each experiment has been produced as well as how to interpret the results and gain insights on how the workflow can be used to model more complex thermal management systems.

You will learn how to:

• Understand how a simple Thermal Management System (TMS) for a hybrid-electric aircraft can be modeled using the Liquid Cooling Library (LCL) from Modelon.
• Use Modelon Impact's Physics-based Solver (PbS) to conveniently solve steady-state flow balancing problems.
• Utilise Modelon Impact's system and component views to visualize the results of different set experiments
• Use multi-execution simulations to carry out domain explorations and sensitivity analyses for key design parameters in a TMS

Background Information

The Aerospace industry is in urgent need to drastically reduce its carbon emissions in order to fulfill the necessary requirements agreed on in the Paris climate agreement. On the one hand, disruptive technologies are under investigation such as using hydrogen as an alternative fuel for driving the aircraft's propulsion systems. A more incremental approach looks at partially reducing the required load from gas turbines by supplementing the aircraft's propulsion system with an electric motor resulting in a so-called hybrid-electric propulsion system. Electric motors can be used to partially or completely power the aircraft depending on the phase of flight. Nonetheless, hybrid-electric aircraft still poses many technical challenges during the design phase. Not only will the additional components of the thrust generating electric propulsion system (EPS) contribute to the weight of the aircraft, but they will also generate unwanted heat during operation. This poses some additional effort during the design of the thermal management system (TMS) for the aircraft, which now needs to cool not only the conventional equipment but also the electrical motor, battery and inverters which make up the EPS.

Thermal management systems (TMS) typically consist of a coolant that is pumped through a pipe network around the aircraft. The coolant flows over the components making up the conventional and electrical propulsion systems, evacuating any unwanted heat in the process. Depending on the complexity of the aircraft, the heat-generating components can be located far from one another, thus the TMS can consist of split points leading to multiple fluid branches which then merge before flowing back to a fluid reservoir. A key design problem to be solved is to determine the optimal layout and sizing of the thermal management system, namely, dimensioning of the pipe branches and design flow rates in each branch such that all components can be kept below their maximum permitted temperature level.