Compact heat exchangers featured in innovative bleed systems could be early damaged when used in severe operating conditions (temperature, pressure and vibrations) such as the ones to be encountered in UHBR nacelle. The objective of this topic is to gain knowledge on physics involved in heat exchanger deterioration. Hence, models which can deal with multi-scale and multi-disciplinary physics shall be built, communicating between each other, with the objective to accurately simulate real operational conditions. Furthermore, sensitivities analysis, design of experiments and probabilistic approach shall be coupled with these models. Finally, innovative virtual demonstration means shall be developed to replace experimental validation. Please refer to the full topic descriptions document published in this call.