 # BETTER INSIGHT INTO PRODUCT BEHAVIOUR USING COMPUTATIONAL FLUID DYNAMICS BeaconIndiaComments off. What is Computational Fluid Dynamics(CFD)?

Computational Fluid Dynamics (CFD) is the utilization of applied physics, mathematics, and computational programming to imagine how a gas or fluid streams and also how the gas or liquid affects objects as it streams past. Computational Fluid Dynamics depends on the Navier-Stokes equations. These equations depict how the speed, weight, temperature, and thickness of a moving liquid are connected.

There is a wide range of factors that play a part in fluid flow applications as designs are complex. Utilizing Computational Fluid Dynamics (CFD) give users the ability to simulate the product’s execution under a wide array of working conditions. This gives engineers an understanding of the pressure, flow and warm characteristics of their product in order to ensure performance and reliability. This quest inspired history’s greatest minds to develop the science of Fluid Dynamics and it’s equations.
∂ρ/∂t+div(ρU)=0
(∂(ρU))/∂t+div(ρUU)=-∂ρ/∂x+div(μ grad U)+[-∂(ρ(u ̀^2 ) ̅ )/∂x-∂(ρ (u ́v ́ ) ̅ )/∂y-∂(ρ (u ́w ́ ) ̅ )/∂y]+S_Mx (∂(ρU))/∂t+div(ρUU)=-∂ρ/∂x+div(μ grad U)+[-∂(ρ(u ̀^2 ) ̅ )/∂x-∂(ρ (u ́v ́ ) ̅ )/∂y-∂(ρ (u ́w ́ ) ̅ )/∂y]+S_Mx
(∂(ρV))/∂t+div(ρVU)=-∂ρ/∂y+div(μ grad V)+[-∂(ρ (u ́v ́ ) ̅ )/∂x-∂(ρ(v ̀^2 ) ̅ )/∂y-∂(ρ (u ́w ́ ) ̅ )/∂z]+S_My (∂(ρW))/∂t+div(ρWU)=-∂ρ/∂z+div(μ grad W)+[-∂(ρ (u ́w ́ ) ̅ )/∂x-∂(ρ (u ́v ́ ) ̅ )/∂y-∂(ρ(w ̀^2 ) ̅ )/∂z] +S_Mz
(∂(ρW))/∂t+div(ρWU)=-∂ρ/∂z+div(μ grad W)+[-∂(ρ (u ́w ́ ) ̅ )/∂x-∂(ρ (u ́v ́ ) ̅ )/∂y-∂(ρ(w ̀^2 ) ̅ )/∂z] +S_Mz (∂(ρW))/∂t+div(ρWU)=-∂ρ/∂z+div(μ grad W)+[-∂(ρ (u ́w ́ ) ̅ )/∂x-∂(ρ (u ́v ́ ) ̅ )/∂y-∂(ρ(w ̀^2 ) ̅ )/∂z] +S_Mz
(∂(ρ∅))/∂t+div(ρ∅U)=div(ℶ_∅ grad ∅)+[-∂(ρ (u ́φ ́ ) ̅ )/∂x-∂(ρ (v ́φ ́ ) ̅ )/∂y-∂(ρ (w ́φ ́ ) ̅ )/∂z]+S_∅ (∂(ρU))/∂t+div(ρUU)=-∂ρ/∂x+div(μ grad U)+[-∂(ρ(u ̀^2 ) ̅ )/∂x-∂(ρ (u ́v ́ ) ̅ )/∂y-∂(ρ (u ́w ́ ) ̅ )/∂y]
Extremely difficult to solve and complex which cannot be solved by hand
Software Revolution:

• That uses methods and algorithms to predict
• How the liquids and gases behave ?
• How they work with the product we design ? In the design world we call this COMPUTATIONAL FLUID DYNAMICS
What can you do with CFD Analysis?

• Challenges can be solved before they turn into serious problems
• Evaluate product performance
• Complements actual engineering testing
• Helps understand defects, problems and issues in product/process
• Enable higher quality product
• Reduces engineering testing costs
• Avoid costly prototype testing
• Provides comprehensive data not easily obtainable from experimental tests

Why should you use CFD analysis?

• Fluid affects the performance of almost every device and structure
• Fluids are always a serious factor
• It takes energy to move a car or to pump water through a pipeline
• By understanding the forces that effects the fluid dynamics
• You can make critical design decision that reduce energy consumption and improve efficiency.

Risk Reduction:
Products vehicles and structures often fail due to miscalculations or judgment error of fluid behavior.   Examples of Computational Fluid Dynamics
Internal Flow- Valves, Pumps etc.,

Flow Control Devices:

CFD is used to study the flow through a wide range of flow control devices:

• Valves
• Regulators
• Orifice plates
• Venturis
• Jet pumps
• Diffusers
• Nozzles
• Cyclone Separators
• Mixing devices
• CFD can be used to determine:
• Pressure drop
• Flow rate
• Spring force
• Surface friction
• Fluid temperature
• Mixing rate
• Particle paths
• Turbulence
• Efficiency
• Aucostics  External Flow- Automotive, Aerospace, Marine etc., Automotive and Aerospace Components

Applications of CFD for automotive and aerospace components:

• Drones
• Wing Span
• Automobiles
• Jets
• Safety gears (helmets)
• Sub-marines
• Missiles & torpedoes
• Launching System
Parameters that can be determined:

• Drag and lift force.
• Acoustics.
• Efficiency.
• Pressure contour
• Temperature distribution
• Velocity profile

Heat Transfer-Electronic cooling Electronic Components

Applications of CFD for automotive and aerospace components:

• Transformers
• Computer boards
• Control Panels
• Circuit boards
• Thermoelectric Cooler
• Heat pipe compact model
• Thermostats
• Insulated- bipolar transistor
• Electronic switches
• Two resistor compact model Parameters that can be determined:

• Heat Transfer
• Heat Flux
• Temperature distribution
• Joule heating calculator
• Fan selection and Optimization
• Heat Sink Optimization Rotating Components-Turbines or compressor Rotating Components
Application of CFD in rotating components

• Propellers
• Fans
• Turbines
• Compressors
• Rotors
• Windmill
• Electric motors
• Agitators in mixing machines
• Blenders
Parameters that can be determined using CFD

• Pressure drop
• Flow rate
• Temperature drop
• Flow velocity
• Calculation of lift and drag on wind turbine blades
• Heat transfer
• Turbulence  Non-Newtonian Fluids- Bio Medical Applications of CFD in Bio Medical

• Cardiovascular Stents
• Respiratory devices (masks, ventilators)
• Respiratory system
• Flow through Ventricles
• Life support systems
• prosthetic heart valves
• ventricular assist devices
• Haemodialysis systems Parameters that can be determined using CFD

• Air flow
• Blood pressure on vein walls
• Simulating blood flow
• Mixing of blood and platelets
• Resistance to flow in arteries
• Interpret fluid stresses in valves
• Pre-implantation analysis of prosthetic valves/ assist devices • LED lighting systems
• Automotive light simulation
• UV Curing lights
• Signages
• Traffic/signal lights
• Domestic lightings Parameters that can be determined using CFD

• Temperature distribution
• air flow patterns within tubular light guides HVAC- Heating, Ventilating, and Air Conditioning HVAC
Applications of HVAC

• Clean room
• Heat pump systems
• Chimneys
• Boiler Systems
• Refrigeration Systems
• Domestic Air conditioning/Cooling
• Industrial cooling systems Parameters that can be determined using CFD

• Predicted Mean Vote (PMV)
• Predicted Percent Dissatisfied (PPD)
• Temperature and humidity
• Pressure differential
• Draft Temperature
• Air Diffusion Performance Index
• Contaminant Removal Effectiveness
• Local Air Quality Index
• Thermal Comfort
• Air flow optimisation/ air flow rate •
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