Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - PIPS (Passive Ice Protection System)

Teaser

The PIPS project addresses the specific aeronautical challenge relative to the improvement and optimization of nacelle/engine integration to reduce drag and save weight thanks to high technology devices leading to significant CO2 savings.The ultimate goal of this project is to...

Summary

The PIPS project addresses the specific aeronautical challenge relative to the improvement and optimization of nacelle/engine integration to reduce drag and save weight thanks to high technology devices leading to significant CO2 savings.
The ultimate goal of this project is to replace the today ice protection systems mounted on the surfaces of engine intakes by a two-phase passive thermal system with the following main benefits:
• Reduction of fuel consumption and raise of the engine effectiveness by the use of a highly efficient thermal system for the extraction of heat load from the engine to the protected surface (high heat transfer capacity compared to the two-phase system mass);
• Decrease of mass and ease of thermal icing protection integration by removing the today electro-thermal and pneumatic usual device used to collect power from power plant;
• Increase of reliability of a critical function such as anti-icing by reducing active control and operations;
• Lower impact on environment and operating cost reduction through the use of passive and maintenance free thermal equipment.
At two-phase system level, the main innovation will concern the adaptation of the space qualified product to the specific aeronautical requirements.
TRL6 is considered for the two-phase product in order to enable the European aeronautical communities to propose more efficient aircrafts with less environmental impacts.
The most relevant characteristics to be assessed and managed through this project are:
• The severe and highly variable thermal and mechanical environment around the engine and its nacelle and
• The specific geometry of the protected surface.
This project will so contribute to the strengthening of the competitiveness of the European industry by introducing two-phase heat management systems contributing to the reduction of CO2 emissions and airplane noise, toward an eco-conception and an eco-utilization point of view.

Work performed

During this first period the concept has been specified. A trade-off has shown that for the given requirements and constraints in terms of environment and thermal performances, only a system consisting in several capillary pumped loops (CPL) could transport passively enough heat from the given hot source to the condenser provided a new evaporator design. The resulting breadboarding activities have secured two important points:
- The manufacturing of the new evaporator;
- The concept of heat transfer from blown hot air to the inside of a two-phase system by means of heat sink fixed on the flat surfaces of the evaporator of the CPL.
A specific trade-off has been performed for the condenser which has shown that a design with tubes fixed to saddles imposes that all saddle must cover the entirety of the air intake surface. Preliminary prediction and the PDR (Preliminary Design Review) have concluded that two system designs are possible:
- A three CPL passive system;
- A one CPL active system with a small amount of power need.
The first solution is 3 time heavier while the second is requiring to spend some power to maintain the reservoir of the CPL at a given optimized temperature. The EM (Engineering Model) will consider the second solution. It will enable to prove the concept, validate the prediction and to establish the amount of power necessary to stabilize the saturation temperature of the fluid.

Final results

The innovation realized in the first period of the project is the development of a new CPL evaporator in terms of material (full stainless steel), size (100 x 200), porous wick and design. The concept of capturing the heat by means of heat sinks on a doubled sided evaporator is also new and has been validated. Finally the development of a condenser with different heat flux densities on different position of the condenser is also new. The new condenser design mixes parallel and a series design distribution of heat on curved and complex surfaces. The specification imposes various design cases where the working conditions can vary strongly such as the hot source temperature, the ambient temperature, the heat flux on each zone of the air intake surface. The design of the system takes into account these highly variable conditions to be able to comply the specifications. The project aims at demonstrating the feasibility of the concept on several design cases with a given size of evaporator. The actual design concept allows possible upgrading for other sizes of air intake or for other design cases by changing the size of the evaporator. The success of the project will enable to use wasted hot air for the deicing and thus reduce mainly fuel consumption and CO2 emission.