The purpose of this thesis is to design and study an aircraft which implements the Co-Flow Jet (CFJ) airfoil concept, as well as to study the CAARC standard highrise building.
The design concept is verified mainly by the use of a Computational Fluid Dynamics (CFD) package. A thorough methodology for geometry and mesh generation is developed, and subsequently applied to the two cases.
The first case studied is that of the CFJ Airplane (CFJA). It consists of a three dimensional, highly blended, flying wing geometry implementing the Co-Flow Jet airfoil concept. Though a thorough comparison to a baseline geometry, it is shownthat usage of the CFJ airfoil cross-section greatly improves aircraft performance by increasing lift, reducing drag, and providing a source of thrust over the operational range of angles of attack.
A steady state CFD simulation is used for this case, as the air flow around an airfoil cross-section is inherently steady for attached flows. CFD results are used to support the “Engineless Aircraft” concept, where the CFJ airfoil is used as the sole form of propulsion.
The second case studied consists of a rectangular high-rise building undergoing a wind condition with Mach number of 0:1 and a Reynolds number of 160000. Due to the non-streamlined geometry of the building cross-section, aerodynamic instabilities due to fluid separation are present, and therefore an unsteady CFD analysis is necessary to fully resolve all of the flow phenomena. Preliminary steady state results are presented, and a plan is laid down for the future study of this highly complex case.
Results are presented for a variety of angles of attack in the case of the CFJA, and for the main flow direction in the case of the CAARC building. Results are compared with baseline geometry in the case of the CFJ Airplane. The CFJ Airplane case is simulated using a 3rd order steady state scheme, which is sufficient to achieve valid results for the flow regime. The CAARC building, which has inherent flow separation, requires the use of high order schemes.
Source: University of Miami
Author: John Aguirre