Ram air channel or NACA channel is used to direct the ambient air for various purposes in an aircraft, such as pressurizing the cabin or as a coolant to heat exchangers and even more other applications like a cooling of the coolant. It is designed; such that it supplies the required amount of ambient air for various operations as mentioned, even aero-dynamical features should be taken into consideration while designing.
In past, the developed prototypes are to be designed first and then experimented to optimize the design which gives accurate predictions and makes easy to understand the phenomenon occurring. These methods can lead to lot of waste in resources and time, in order to avoid these, some new mathematical methods have been implemented before finalizing the prototype which might save resources, time and minimize the possibility of having wrong outcomes. Some additional steps are included during calculation stage prior to the prototype stage; they are the computer aided simulations. These simulations can be as accurate as real time simulations and can bring closer to accuracy rate which is a needed prior to prototype stage.
The aim is to design a tool chain for a Ram air channel which in turn is used to optimize the flow, then supplied to heat exchangers for cooling the hot refrigerant from the avionics systems. The requirements of the heat exchanger are decided on the applications it is used and the range of temperature to be cooled.
In this study work, firstly estimate the size of the heat exchanger for the required performance, followed by the geometry of Ram air channel designing in CAD application so that it maintains the required amount of mass flow rate for the performance of heat exchanger. Finally these both components are implemented in simulation loop to iterate the designs of NACA channel in order to get the final model to optimize the flow for a heat exchanger.
Source: Linköping University
Authors: Nangunoori, Chetan Kumar | Kumar Bhaskar, Ravichandra Kumar