Many airlines compete on the basis of the in-flight experiences they offer, whether these are extensive entertainment packages delivered on seatback touch screens, free Wi-Fi connectivity, or more spacious seating. But some of the most important aspects of passenger comfort are the cabin’s noise, temperature and humidity levels and getting them right is essential – even if airline customers only notice them when they go wrong. Creating an optimal cabin environment, however, requires striking a balance between a complex interplay of multiple factors, including the use and distribution of structural and insulation materials, cabin airflow and pressurisation of the aircraft.
Turn Down the Volume
The biggest sources of in-cabin noise are the aircraft’s engines and the air flowing over its fuselage during flight, which can be heard as either a hum or a roar depending on the successof in-cabin noise reduction. Added to this are the internal heating, ventilation and air conditioning systems.
The use of insulation to dampen sound has to be balanced by the need to keep aircraft weight low in order to reducefuel consumption. Advances in composite material design make it possible to develop relatively lightweight sound insulation. But finding the most effective material and optimising its distribution within a cabin to control the propagation of acoustic vibrations, while taking into consideration the many variables that affect sound levels, such as the trim used or the aero-acoustic performance of the air supply duct, is not straightforward. Given the expense of building engineand fuselage prototypes to test designs, it’s important to choose the right simulation and analysis software to model the efficiency of a full range of shape and materials, including structural and poro-elastic ones within a wide range of possible use cases.
That’s why Hexagon Manufacturing Intelligence’s simulation and analysis software solutions enable multiphysics simulation capabilities. These allow aircraft design engineers to combine computational fluid dynamics, with structural dynamics and acoustics software solutions to design quieter aero-engine and lighter aircraft structures with lower interior noise levels without the need to build physical prototypes to test different design iterations.
Blowing Hot and Cold
Crucially, our software enables designers to combine two or more simulation and analysis packages so that they can simultaneously consider multiple factors, including temperature, humidity, pressure in its surrounding mechanical structure. Temperature within aircraft cabins is hard to regulate because they are non-uniform thermal environments. Not only is temperature-treated air fed into thecabin through separate distribution points dotted around the cabin, there is also an uneven spread of heat loads within the structure. Economy class, for example, typically contains a higher density of passengers generating body heat than first class. And the galleys, where food and drinks are stored and prepared, as well as the touch screens on seats, are further sources of heat.
Co-simulation and analysis solutions allow designers to take into account a full range of factors so they can optimise heat and humidity distribution throughout the cabin, as well as airflow through the engine. Hexagon’s computational fluid dynamics (CFD) software, for example, harnesses a unique method to accountfor human body temperature and comfort within these calculations which can additionally be combined with our structural or acoustics simulation models.
Find out more about how Hexagon’s co-simulation solutions help aircraft designers more closely simulate passengers’ real in-flight experience and develop environments that greatly improve customer experience.
