AHEMD BODY COMPARING TWO MESHING METHODSNabeel Fathi
AUTOMOTIVE AERODYNAMIC PROBLEM
Problem Description
• The Ahmed body is widely used in the automotive aerodynamic literature, to simulate the airflow over a simplified, ground vehicle geometry.
• In this research two types of meshes were tested to simulate the external flow over Ahemd body.
• Ansys work bench was used, and results are compared.
• Mesh 1• Face Sizing• Inflation 10 layers
Ahemd Body
Inflation layers
• Mesh 2• An additional 3d body was modeled to enfold the Ahemd body.• The 3d body mesh was body sized, meshing the fluid around the Ahmed body.• Same element size was used for both cases.
Ahemd Body
3D enfolding body
• Mesh 1 • Mesh 2
Velocity Contour
• Mesh 1 • Mesh 2
Velocity Vector Rear
The velocity profile of the fluid behind the Ahmed body.
Mesh 1 Mesh 2
Velocity Profile 0.08 m behind the body
Velocity Profile 0.18 m behind the body
Computational Effort.
• The number of elements was much higher for mesh 2.
• The computational time was high for mesh 2.
• The two results were relatively close.
The End