Integrating Computation Fluid Dynamics into Mechanical Design

Use of CFD Simulation in the beginning of product Development cycle by Mechanical Design Engineers has become an emerging trend. Previously faced challenges like difficult to integrate, cost, etc. in utilizing CFD Analysis has gradually being overcome as flow simulation becomes more embedded in the mechanical design process. As a result simulation results are becoming available practically as quickly as modifications are done in the design cycle, thus CFD plays a crucial role in design, decision making as well as optimization processes.

CFD Analysis is employed to design products that rely on fluid flow and heat transfer phenomena, like airplanes and automobiles; to enhance its performance. CFD Analysis utilizes computer to employ numerical methods and algorithms to solve and analyze problems adhering to fluid flows and simulate the interaction of liquids and gases with surfaces defined by boundary conditions. This aids in predicting flow velocity, temperature, and species concentrations that are used to enhance the products design and development processes.

Benefits of Simulating Early

Simulating Mechanical Design early in development cycle helps in developing an efficient design and helps in reducing the time spent in the verification and testing phase of product development. It enables manufacturers to minimize the number of prototypes essential to pass quality tests and avoid unnecessary changes after design completion. Simulation is usually embedded in the computer aided design (CAD) application and relocated from CAD to pre-processor applications. This keeps the engineer in an acquainted environment and eliminates the additional step of relocating geometry to an additional application.

Challenges in executing CFD Analysis

• CFD codes that are linked to CAD software take a copy of the 3D geometry, convert it by means of a neutral format like Parasolid or ACIS, and include boundary conditions to generate a model for fluid analysis that loses intelligence like assembly hierarchy, constraints, and features.
• As Empty flow space that forms the basis of the fluid model does not exist as a discrete object in the original CAD design, most integrated CFD codes extract all of the cavities from the CAD model, add them to the feature-tree as new objects, and then grid them separately using grid generation software.
• The data persistence as well as links to the original CAD model is lost, that makes it impossible to retain model history as well as parameterization.

Combating the Challenges Faced

• Requirement of high level expertise for CFD Simulation is overcome by means of advance CFD tools that are fully embedded in mechanical design.
• CFD software operates as an extension of CAD software, automates schedule simulation operations and allows direct interaction between CFD software and CAD data to retain pace with continuous design changes.
• CAD data is utilized for CFD simulations without any requirement for translations or copies.
• CFD software utilizes same feature tree and geometry model as CAD software thus design modifications are executed directly in the CAD system.

·         All auxiliary data like material properties and boundary conditions are linked with the CAD model.

·         CFD software stores fluid flow parameters, temperatures, flow rates, etc as object-based features, maintained in the feature tree like other object-based data, and applied directly to update the simulation software. This allows a large number of model variants to be simulated automatically.

Thus, CFD Analysis by means of CFD software uses CAD data, automatic grid flow space, and manages the flow parameters as object-based features eliminating the need for engineers to understand the computational part of CFD. Integrating CFD into the mechanical design provides rapid and more certain results that justify the cost for executing CFD Analysis.