Optimization of IP duct vane articulation for improved cabin airflow directivity 2019-28-0132
CFD simulations are effectively used to cut down the vehicle development period and to completely understand the interaction between the cabin thermal comfort and mobile air-conditioning system. While the methodologies are well established to quantify the passenger thermal comfort behavior in a vehicle, the investigations to quantify the cabin airflow directivity still requires in depth understanding, even though a vast number of studies are available on cabin cool down performance.
The air velocity achieved at driver and passenger aim point is one of the key parameter to evaluate the automotive air-conditioning performance. The design of duct, vent and vanes has a major contribution in the cabin air flow directivity. However, visual appearance of vent and vane receives higher priority in design because of market demand than their performance. More iterations are carried out to finalize the HVAC duct assembly until the target velocity is achieved. The current process is time consuming as the vanes are rotated manually and simulation is done for each vane angle and requires post process for every iteration. It requires more number of simulations to achieve the target value. The major requirement here is to significantly reduce the manual design time and decrease the pre and post processing time.
In this work automated simulation of vane articulation study carried out using CCM+ and HEEDS tool. The minimum and maximum vane angle are defined as parameters and face level velocity is defined as response. Depending on the optimization technique and number of iterations defined in HEEDS, the vane angle will get updated and the design iterations proceeds automatically till the number of iterations are met.
The obtained results are compared with test data and correlated well. This process is useful in finalizing the duct assembly design during the concept phase of new programs. This process significantly aids in reducing the manual effort of design and simulation as runs are automated resulting in overall reduction of time required for the vane articulation studies.