'Humidity Optimisation Tool:
Outside humidity treatment is a main contributor to aircraft ECS (environmental control system) power requirements. To reduce this power it is needed to know exactly the not to exceed outlet humidity at the pack outlet. Liquid water at Low Pressure ducting participates to cabin cooling but, if this quantity is too high, a fog can be seen.
The purpose of the “Humidity Optimization Tool” project is to develop a tool able to predict generation and growth of water fogs in the ECS, in order to avoid them. The project can be separated into three sub-topics:
1) Determination by tests of a visibility fog criteria based on physical properties (air speed, liquid water content, blowing temperature, droplet size, etc.)
2) Development of a 0D tool to predict the size of the water droplets (liquid or ice) downstream a: (i) Heat exchanger, (ii) Pack outlet turbine and (iii) Mixmanifold
3) Validation of this tool
The proper implementation of this research requires two-phase flow expertise in two different fields: (i) numerical modelling and (ii) measurement techniques.'
'In all-electrical aircrafts, the corresponding electrical ram air fan should be optimized in order to improve its current design in two aspects: a)generate pressure drop at low flows without surge issues; b)cooling of the fan electrical motor at high inlet air temperatures.
The ECS control logics produces two main typical operating points, one with high flow when the ram-air fan creates enough flow to cool both the ECS main heat exchanger and the ECS motor stator, and the second when it only needs to provide a low airflow for the latter necessity. As the pressure drop is similar in both situations but the flow very different, this creates surge problems that should be eliminated for adequate operation.
Meanwhile, the fact that the ram-air fan is located downstream the ECS main heat exchanger implies that the air inlet arrives to the fan at high temperatures, what difficulties its own correct electrical motor cooling, both from a mechanical and electrical points of view.
Considering these objectives, a new fan concept will be selected from available bibliographic and consortium expertise, and designed using the consortium skills in deep fundamental fluid mechanics and heat transfer knowledge (Technical University of Catalonia - UPC ), advanced CFD tools and aerodynamic know-how (Termo Fluids - TF) and engineering capacities of a fan manufacturer (BALTOGAR ). The proposed design related to surge problem will be implemented in a prototype and tested accordingly. In a similar manner, a solution for electrical motor cooling will be found.The final solution must also consider its impact on the whole ECS pack, in order to maintain its global performance objectives.'
'The project intends to develop a new Electric Machine Modelica Library with improving functionalities for an accurate design and simulation of motors and generators.
New Externally Excited Synchronous Machines, Permanent Magnet Synchronous Machines (PMSM and BLDC) and Asynchronous Induction Machines (IM) models in Modelica language including spatial harmonics and nonlinear saturation behavior, as well as improved thermal model for the thermal evaluation of the machine, are the main objectives of the proposed project, together new software tools with GUIs for guided model design from geometric motor considerations and torque and power demand profiles.
Generalized space phasor theory to m phases with arbitrary spatial angle of the coils, and arbitrary number of windings and winding factor of the coils will be considered for the new Library. Constructive harmonics and distortions of flux couplings are taken into account as well.
Also, non-linearity due to saturation and skin-effect on the resistances are considered in updated libraries. Moreover, thermal models able to calculate hotspots and asymmetric windings temperature distribution from the thermal losses into the machine are included in the Library.
A graphical guided Interface for directing the modeling of machines is included in the project.'