Model-based analysis of boundary layer ingestion effect on lateral-directional aerodynamics using differentiated boundary conditions

Abstract

The noteworthy feature of aircraft with distributed propulsion configuration is the integration of a blended-wing-body type airframe and an embedded distributed propulsion system, thus inducing the specific boundary layer ingestion effect. Different boundary layer ingestion effects on the distributed engines may generate asymmetric flow fields on the airframe surface, and then lead to the unique lateral-directional aero-propulsive close coupling. To investigate the lateral-directional aerodynamics influenced by boundary layer ingestion, a new comprehensive computational method based on the differentiated boundary conditions is proposed. This method uses a synthetic three-dimensional computational model including the airframe and multi-engine to analyze the aerodynamic characteristics, and the essential boundary conditions can be extracted from the thermodynamic distributed propulsion system model to represent the different boundary layer ingestion intensities on the left and right engines. Subsequently, detailed model-based analyses of boundary layer ingestion influences on the lateral-directional aerodynamic characteristics are conducted, and the influence regularities under different flight states are revealed. All the results demonstrate that the differentiated boundary layer ingestion intensities on distributed engines can certainly affect the roll and yaw aerodynamic performance of the distributed propulsion configuration aircraft.