Computational Fluid Dynamics

Computational Fluid Dynamics (CFD) is a technique of solving fluid flow, heat transfer, mass transfer, and related phenomenon on a computer by solving the basic conservation equations of mass, momentum and energy.

These equations are very complex and highly coupled and are discretized and converted into a set of algebraic equations so that they can be solved using a computer.

CFD for Automotive

The automotive industry has been at the forefront of adopting CFD modelling and simulation techniques. Diverse automotive applications can be simulated using CFD modelling to gain insight, test what-if scenarios and optimize the final design.

CFD technology can be used for improving vehicle aerodynamics and reduce flow induced noise. This results in a direct improvement in the mileage, passenger comfort and safety. Certain non-core applications such as intake of air filtration, In-cabin HVAC, pumps and heat exchanges can also benefit from CFD and can have a positive impact both on consumer satisfaction as well as the long term performance of the vehicle.

Finally, CFD can be used during the design and troubleshooting of the heart of the vehicle which is the Automotive Power Train. This includes flow manifolds, combustion in IC engines, cooling systems, clutches, breaks, gear boxes, and emission control systems and under-hood thermal management.

 

Air Filter design modifications to eliminate non-uniform pressure drops.

Automotive headlamp cooling.

CFD for HVAC

CFD is used in Heating, Ventilation and Air Conditioning (HVAC) for the analysis of the impact of building exhausts, to predict air flow, smoke and fire risks in buildings, to predict the transfer of contamination, to quantify indoor air quality and to design ventilation systems. CFD’s virtual modeling provides powerful visualization capabilities making it possible to optimize HVAC design parameters without making physical modifications to existing systems.

Building air conditioning (heating as well as cooling) is one of highest operating cost head for large infrastructures such as hotels, airports, hospitals, public places, and shopping malls etc. With increased focus on making these facilities as environmentally friendly as possible, it becomes imperative that the HVAC system is studied in detailed for various design as well as operating conditions. CFD models enable the designers to conduct such studies, giving them complete visibility into possible problem areas and solutions.

 

Evaluating cooling performance to study temperature distribution on passenger seats.

Using standard Navier-Stokes equation for Flow and heat transfer modeling (Temperature contour at 4 feet).

CFD for Chemicals and Process Industry

Chemicals and process industry has a unique challenge of continuously operating the reactors and plants without significant shutdown and with appropriate safety considerations. The amount of insight gained from conducting CFD studies can save operating costs and reduce timelines (by improving yields), reduce environmental impact and understand practical operating limit for a given plant. CFD can also assess effects of potentially disastrous phenomenon like erosion and corrosion which build over a long period of time and are difficult to study in an experimental facility.

 

Existing Design: Flow loop covers partial reactor volume resulting in dead zone.

Modified design: changed impeller spacing to cover entire reactor height. Dead zone removed.

 

CFD models in the chemicals and process industry need to incorporate modelling of chemical reactions which many times involve generation or consumption of heat, phase change, etc. Over the years, separate reaction modelling software has been incorporated as part of the overall CFD modelling framework so that realistic simulation times can be achieved. The industry many times relies on use of 1D or 2D models in collaboration with detailed CFD models to gain meaningful results from the models. Most new CFD modelling software allows for coupling with external 1D or 3D models.

CFD for Oil & Gas

Computational Fluid Dynamics has applications in all stages of the Oil & Gas industry operation from exploration, production (drilling & extraction), transportation and processing. Applications include flow analysis, coupled fluid structure analysis, environmental impact and assessment studies, plant safety, pollution prediction and fire and other related hazards. The main goal of CFD in the Oil and Gas Industry is to reduce the cost of retrieval, reduce health and safety related risks during operation and minimize the impact on the environment in case of catastrophic failure scenarios.

Most of the oil and gas applications involve multiphase flows (liquids, gases and solids), involve heat transfer and associated phase change. CFD models in these areas of applications are complex and involve experimental validation. However, experimental validations are expensive and extremely time consuming. Also, it is difficult to conduct experiments to cover for all what-if scenarios. Therefore, the product and process development approach in Oil and Gas industry involves judicious use of experiments and CFD modelling.

 

Three phase flow separator.

Path lines for a cyclone separator. Tangential and radial separators improve efficiency of separation.

CFD for Industrial Equipment

Development of industrial equipment such as pumps, valves, filters, heat exchanges, seals, compressors etc. requires significant amount of testing and development effort due to the fact that they operate in a wide range of scenarios and still have to work without defects over their promised life span. CFD models can be used to study the performance of various designs at design and off design conditions and then optimize the designs for various objectives such as cost, life and safety parameters.

 

Studying noise generation due to turbulence and unsteady rotor-stator interaction and predicting and predicting fan noise using Computational Aero-Acoustics models.

Using CFD to evaluate different designs for blades and assembly to improve fan performance.