DALI aims at validating a virtual testing approach so that design and test loop can be shortened and tests can be partly replaced, applied on the development of future generation of compact heat exchangers, for the engine innovative bleed system; with higher requirements and thus damage probability. DALI proposes a fully integrated modelling platform where damage laws will be integrated relying on a multiphysics and multilevel modelling approach. A robust and reliable solution will be implemented based on an improved understanding of specific phenomena occurring during thermo mechanical ageing of heat exchanger in aircraft. The mainstream will enable to reproduce the thermal cycling ageing and its statistical probability by multiphysics simulations, and a set of master datasheets of fatigue curves and damage laws Manufacturing variability (local deformations, initial stress state), and other design variables will be included. The proposed validation scheme includes a set of details of increasing complexity where the simulation approach and the instrumented physical testing will be compared, and iteratively improved, so that real observations of cracking coming from Aircraft exploitation can be predicted. A representative coupon test plan and an innovative measurement to detect cracks initiation in non visible areas will be included. The prediction capacity will allow mastering the heat exchanger behaviour and the mean-time-between-failures, MTBF, to tailor the heat exchanger design, including sensitivity analysis for potential optimization. DALI stands on members’ skills and their cross advanced FEM knowledge capacities to enable a seamless technical coordination through the combination of customized experimental validation and advanced simulation so that a) an accelerated test approach can be implemented for in service life assurance, b) a degradation law that could be used in combination with a simplified and accurate simulations for future CHX precooler sizing.

Selective Laser Melting (SLM) is key for improved design and production process of aviation parts. Applied to heat exchangers (HX), it could dramatically improve global eco‐efficiency through access to radically new designs and open horizons in terms of shape, weight, efficiency. Nevertheless, some questions need to be solved regarding capability of Additive Manufacturing (AM) to manufacture thin walls, small holes/gaps, low overhang angle, resulting surface roughness and mechanical strength. AManECO aims to enhance knowledge of metal AM and, specifically, the capability of SLM process to manufacture thin layers and wall thickness with adequate surface finish using AlSi7Mg0.6 and INCO 718 materials. In particular, to investigate aerothermal and mechanical performance of thin walls, to predict them in the design of AM-HX and consequently, be able to optimize the HX´s design process in an Eco-friendly way after knowing the limits of the metal AM technology. For this purpose, testing samples will be designed and manufactured to characterize in terms of surface properties, pressure resistance and gas tightness evaluation, equivalent stiffness and aerothermal properties. Besides, numerical studies based on FEM and CFD simulations will be done. Then, a representative design of HX based on the initial SOA of AM limitations will be optimized with the gained knowledge. These designs, before and after optimization, will be processed and characterized. Then, a Life Cycle Inventory (LCI) database will be created to evaluate the ECO potential of the innovative HX. AManECO will enable to: - Increase efficiency of HX up to 10%. - Reduce the overall of HX manufacturing costs by 30%. - Reduce material waste and scraps by 15 % per component. - Reduce time-to market up to 1 month. A multidisciplinary consortium, with experts in HX design and AM (TUHH, LORTEK, FIT), samples characterization (CIDETEC, MU-ENG), numerical simulation (EPSILON, TUHH), and life cycle assessment and eco-design (CTME), has been defined.

PALOMA will design and test a passively actuated opening system that will allow a volume of secondary air flow to be diverted into the engine core area for cooling purposes. Being entirely passive, no external electrical, hydraulic or pneumatic power will be required to run or control the system. The system will use a heat pipe to transfer the necessary heat to a shaped memory alloy (SMA) component whose movement will, through a set of mechanical linkages, open a flap set within the nacelle inner walls. This system will permit an optimisation of the engine thermal management and performance whilst needing minimal maintenance. Based on an agreed set of requirements, the project partners will first perform a trade-off in terms of possible heat pipe and SMA material and geometric forms, followed by their full characterisation. This information will permit a) the design of the system to be performed after a trade-off considering the constraints (positioning, extreme temperatures and aircraft accelerations) linked to the installation of such a system in a nacelle b) the modelling of the system’s behaviour. Having completed the design, a functional prototype will be tested on a specifically design test bench to simulate operation conditions including pressure, temperature and vibration according to the requirements of the DO160, mandatory for all equipment used on aircraft. The results of the tests performed on the functional prototype will be integrated into the design of a demonstrator (which may also be used for flight tests) which in turn will be manufactured and tested. Modelling activities will support the project throughout its execution. The PALOMA solution will be fully European and brings together: a thermal management engineering and modelling company, a heat pipe specialist, an SMA specialist with unique design and industrial manufacturing capabilities and a broad-spectrum engineering company specialised in aircraft and engine integration.

The work proposed in this project focuses on the manipulation i) of fluids in single-phase liquid state and ii) of liquid- vapor interfaces using electro-hydrodynamic effects with the aim of pumping and/or enhancing heat transfers at the interface between a fluid and a solid wall. In the current state of knowledge, the questions must primarily been addressed from a scientific point of view. Indeed, models published in the open literature are not able to describe quantitatively the experimental results available. The main objective is thus to increase the level of maturity of this multidisciplinary topic to open and/or enlarge the application fields it can concern. To this end, fundamental studies will be developed to determine the theoretical electrical, fluidic and thermal models of phenomena occurring when an electric field is applied in a liquid with and without a liquid-vapor interface. A specific study on different fluids will also be conducted to determine their EHD performances according to their thermal factors merit. Simultaneously to these fundamental studies, two specific applications will be explored. The first one consists in the development of an electro-hydrodynamic pump for hybridizing capillary two-phase cooling systems. The aim is to improve the reliability and performance of such systems for space applications on the one hand, and to broad their field of application to the terrestrial environment without loss of performance on the other hand. The methodology adopted follows a logic of increasing complexity: the study will focus initially on the analysis of pumping capacity depending on the type of fluid, of the applied electric field and of the electrodes design. The aim of this part of the study is to design and to realize an optimized basic module of an EHD pump. To this end, the test bench developed during the preliminary study that the partners have already done will be used. Depending on the desired pumping capacity, this basic module will be repeated n times. Both fluidic and electrical architectures of these n modules will then be defined to design a high capacity EHD pump to be implemented in a two-phase capillary pumped loop operating in ground environment. The robustness of the EHD pumping will be analyzed as a function of vibration stresses to validate the potentiality of uses of such devices in embedded systems (land, air, space). The second application that will be explored consists in coupling the electro-hydrodynamic phenomena, the convective effects and the liquid-vapor phase-change. This part of the project aims to establish the means for the control of liquid-gas interfaces necessary (especially) for the design of enhanced and innovative heat exchangers. Considered situations will cover a static configuration (induced by a dielectric strength of a liquid-vapor interface versus the hydrostatic pressure), a quasi-static situation (same as above but with evaporation at the liquid-vapor interface) and the case of a two-phase flow generated by an imposed pressure gradient or by capillary forces. At the end of the project, thanks to the results obtained, research and development activities will be initiated in the framework of the Technological Research Institute Saint Exupéry in Toulouse. It is therefore planned to develop a hybrid capillary two-phase loop capable to transfer high heat fluxes. This loop will include a EHD pumping system in addition of the capillary pumping. A demonstrator will be realized. It is also planned to realize an optimized evaporator prototype using dielectric strength.