Cd (drag coefficient) and Cl (lift coefficient) are used to characterize a vehicle's aerodynamic performance. These coefficients have been traditionally determined by wind tunnel tests. However, SC/Tetra has been validated for calculating aerodynamic performance with minimum error compared to experiment data. SC/Tetra can model precise underbody details and pipes due to its highly tuned solver that consumes minimal memory. Software Cradle is dedicated to continually improving SC/Tetra's accuracy and capabilities. The company also provides technical support by conducting complex, high level simulations for its clients.
In addition to vehicle aerodynamics, optimization of interior climate control systems is also an important CFD application. Applications include interior heating and cooling (including solar radiation) and windshield defogging and defrosting. SC/Tetra is capable of handling very complicated geometries with its sophisticated and robust grid generator and low memory consumption solver. In addition, SC/Tetra offers unique capabilities for predicting occupant comfort by employing a fully coupled human body thermoregulatory model. This model considers the detailed human body vascular system and individual physiological factors.
Air Conditioner Ventilation Duct
SC/Tetra is used for designing an air conditioner ventilation ductwork. CFD makes it possible to compute efficiently balanced air distribution enabling design optimization where space is extremely limited
- Engine compartment ventilation, such as radiator cooling performance, is an important CFD application. SC/Tetra is suitable for accurate computations of highly complex geometrical models including engine, radiator fan, accessories, and vehicle underbody details. This analysis can including calculating the pressure drop through the radiator.
Side View Mirror
In addition to simulating vehicle aerodynamics, CFD is also used to optimize the shape of individual vehicle components that affect the overall aerodynamics. One example is a side view mirror. The side view mirror must satisfy a range of design criteria including being positioned to reflect the proper views, minimizing drag, repelling droplets of water on the mirror surface, and minimizing production of aerodynamically induced acoustic noise. SC/Tetra can be used to evaluate different design concepts in a short amount of time.
Intake and exhaust manifolds performance are usually first simulated in steady state to ensure a uniform pressure distribution. Transient analysis is used to determine if reverse flows exist. In addition to internal flow simulation, an exhaust manifold should be thermally simulated to ensure correct material selection and material thicknesses.
Analysis of torque converter used in automatic transmission of a vehicle requires calculation that accounts for rotating boundary. It is possible to evaluate torque values as well as pressure (force) imposed on each component.
For engine valve analyses, the swirl ratio and/or tumble ratio are important fuel mixture parameters that greatly influence combustion and emissions. SC/Tetra is used for calculating and optimizing inlet and exhaust valve design geometries.
Analysis of Duct of Engine Port
Flows of engine port can be analyzed using mesh adaptation analysis. The area where mesh should be more refined can be automatically detected using this function, which refers to analysis results. By re-generating mesh and re-processing calculations, more accurate results can be obtained, which do not depend on the mesh generating skill of analysts.
Flow Analysis of Engine Port
This type of analysis is designed to predict the inflow rate of air that depends on valve lift and degree of attachment. Analysis time and memory can be minimized by applying a model in 1/2 scale when a symmetrical geometry is used. Automatic script processing is also possible using valve lift and degree of attachment as parameters.
Analysis of Gasoline Sloshing of Tank
Fluid sloshing occurs within gasoline tanks of vehicles and ships, deriving from external periodic vibration. This may cause damages on tanks or fuel leakage. It is possible to predict fluid vibrations changes in pressure of the container by using free surface function called VOF (volume of fluid). Design engineers can identify ideal container geometry that prevents concentration of loads by examining the flow and pressure.
Thermal management is crucial due to high output characteristic of vehicle headlights, especially when LED headlights are used, which have low heat-resistant temperature. Heat from light source is emitted to open air as radiant energy along with heat conduction and convective heat transfer. Highly accurate prediction of temperature is possible by accounting for reflector and radiant energy reflectivity and absorbance degree of cover material.
Heat Exchanger (Radiator, Inter-cooler, Oil Cooler)
A CFD simulation of an heat exchanger e.g. a radiator, considers two working fluids - usually air and water/coolant. CFD is used to determine the efficiency of the heat exchanger which is directly a function of the velocity of the fluids at the wall. CFD also predicts whether the coolant flow is uniform within the heat exchanger. Coolant flows of water jacket in engine block can also be analyzed, as the mechanism is principally the same as heat exchanger
Analysis of the Fluid Flow inside In-cylinder (Mesh Element Distribution and Surface Pressure Distribution)
Complicated transient flow occurs in cylinders due to opening and closing of engine valves. Opening and closing of valves can be analyzed by overset mesh function that calculates layered in-cylinder and valve mesh elements. As contact between objects can be taken into account in this analysis, which was formerly difficult to examine, it is possible to draw more accurate prediction of flow field that is determined by opening and closing motions.
Aerodynamic Analysis of Formula Car (Surface Pressure and Streamlines)
In Formula car races, it is important to reduce air drag for faster and more stable driving. Simulations of airflow over a racing car enables an understanding of the mechanisms behind air drag with visualizations of the complicated flow patterns and pressure force on the car body, thereby contributing to the improvements of body shape.
Analysis of the Air Flow in Large Vehicle Interior (Streamline and Distribution of Surface Temperature)
Thermal comfort of bus interior space can be evaluated. Air-conditioning effects and thermal loads can be taken into account. Passengers can be represented using JOS (thermoregulation) models, which accounts for blood circulation and thermal management function of body, as well as effects of clothing. Using this analysis, it is possible to evaluate the level of passenger comfort by calculating air temperature as well as skin temperature and perspiration of passengers in vehicle indoor space.
Analysis of a Water Jacket
A water flow channel placed for cooling the heat from engine cylinders is called a water jacket. A water jacket is designed in such a way to make the flow speed fast at the portions that particularly need to be cooled, and also to avoid air pools. In SC/Tetra, mesh can be generated automatically even for this kind of complicated, large-scale geometry.
Thermal Analysis of a Vehicle Headlamp (Temperature Distribution)
Thermal management is crucial due to high output characteristic of vehicle headlights. Heat from light source is emitted to open air as radiant energy along with heat conduction and convective heat transfer. Highly accurate prediction of temperature is possible by accounting for reflector and radiant energy reflectivity and absorption of cover material.
Analysis of Liquid Film
Effects of paints can be analyzed using liquid film model. Spray paints from nozzle can be modeled and liquid particles change to a liquid film when reaching on the wall. Analysis using liquid film model requires less calculation load compared to free surface analysis function, which accounts for surface tension and angle of contact, which makes it suitable for analyzing expansion of thin liquid film.
Analysis of Electrostatic Spray
This is an example where particle tracking was used to analyze spraying effects of paints from spray gun. Effects of paint particles can be evaluated, which are emitted through electrostatic field created by voltage applied from spray gun, while being exposed to electrostatic force. It is also possible to calculate the adhered position of paints on target object, and adhered thickness.
Predicting the performance of a single heat sink is a common first step for thermal simulation. Thermal conduction is influenced by the spacing and thickness of the fins, and the heat-transfer coefficient is influenced by the air velocity over the fin surface.
Some heat sinks are integrated with a fan. SC/Tetra can be used for simulating these systems by including the fan rotation model, a primary source of cooling. The steady state performance of the heat sink is calculated quickly. Fan rotation introduces a transient component.
Power Supply Unit
The power supply unit which transforms voltage emits large amounts of heat which is dissipated by both forced convection from fans and natural convection. HeatDesigner stably computes natural heat dissipation using predetermined calculation parameters for electrical and electronics equipment.
Analysis of a Sirocco Fan
Flow of a sirocco fan can be analyzed. The relationship between rotation number and output flow rate can be examined by using moving region function to induce blade rotation. Visualizing the flow and pressure enables analysts to improve blade geometry as well as identify fan-generated noise by using aerodynamic noise function.
Flow Analysis inside a Chassis (Particle Tracking)
This is a simulation example of electronics cooling that uses fans. It is essential to apply the most appropriate type of fan and determine located position for forced air-cooler design. By conducting thermal analyses, engineers can check whether the output air flow rate and velocity towards cooling target components meet the requirements. Overall device can also be optimized by evaluating the ideal geometry of heat sinks along wind paths.
Car Audio and Navigation Systems
Car audio and navigation systems generate a significant amount of heat. This subjects the inside of the automotive dashboard to extremely high temperatures. Optimum system integration dictates appropriate analysis of the potential thermal problem. HeatDesigner and scSTREAM are suitable tools for this analysis which requires a high degree of accuracy. Both HeatDesigner and scSTREAM efficiently handle large models which is needed for resolving fine geometric details.
Due to the increasing demands for miniaturization and the improved in output power, it is critical to ensure heat dissipation capability for projector design. Prior evaluation on fan design and component layout allows designers to assess and consider ways to increase the heat dissipation efficiency.
Thermal design is vital when developing a smartphone, as the temperature is likely to increase due to the sealed casing. Simulating thermal flow prior to the manufacturing enables engineers to adjust component layout and materials and optimize the design.
Compressible Flow Analysis of a Hypersonic Transport Plane
This is an example of analyzing supersonic transport. Fluid pressure increases as flying speed exceeds speed of sound. The type of phenomena occurs under such condition cannot be actualized in the presence of low speed such as shock waves. In order to predict the changes in flow field, it is important to use analysis method that accounts for compressibility of fluid.
Analysis of the Flow inside Gear Pump (Mesh Element Distribution)
Gear pumps are widely used as constant volume pumps for hydraulic power units of industrial machinery. In this type of analysis, surrounding fluid is transferred as mesh elements of gear rotate. Using overset mesh function, it is possible to account for the effect of gears engaging with each other.
Analysis of a Mixing Tank (Mesh Element Distribution)
Mixing tanks are used in various processes for many industrial equipment. In this type of analysis, mesh elements of blades rotate, which gives force to surrounding fluids to create mixing motion. Overset mesh function can be used to account for near or direct contact between blades when multiple blades are involved as shown in diagram.
Analysis of Air Flow Generated by Roots Blower
A roots blower is a pump that performs air intake and exhaust by a pair of non-contact, counter-rotating rotors. In this analysis, the mesh elements move as the rotors rotate. It is possible to account for the effect of rotors engaging with each other by using overset mesh function.
Flow Analysis of a Heat exchanger Fan for Refrigerator
Flow of cooling fan is determined by blade geometry, the shape of the fan, and allocated position. Using SC/Tetra, highly accurate flow analysis can be conducted, which accounts for the effects of shapes of surrounding devices as well as the air flow generated by the fan.
Room Ventilation I
scSTREAM can be used to evaluate air-conditioning performance within a room in a house, office, or any large interior space. This fluid analysis calculates the distribution of the air velocity and temperature throughout the design space. This enables calculation of exact numerical values within any specific area. This is much more precise than the conventional thermal loading calculation. CFD enables inclusion/calculation of gas concentrations, solar radiation effects and dew condensation. scSTREAM is also often used for analyzing clean room designs which require precise air control.
Room Ventilation II
scSTREAM automatically calculates heat generation by sunlight using a solar radiation function. The user is provided with parameters to control solar radiation, such as transmission rate, glass absorptivity, and absorptivity of the object surface that is exposed to the sun loading. By including specific heat considerations, scSTREAM can be used to calculate performance of a heat storage system which accumulates solar energy during the day and uses it at night. scSTREAM can also consider thermal buoyancy such as the natural ventilation caused by differences in temperature throughout a house.
Gas flow in an Underground Parking Area
CFD is used for determining exhaust fan location and arrangement in an underground parking area. For complex parking area configurations it is especially important to avoid accumulated gas flow. scSTREAM generates an index value to quantify ventilation efficiency. In addition to standard computations of gas flow and gas concentration, the user can also easy determine the differences in efficiency for various fan arrangements and levels of performance.
Air flow around Buildings
High rise communities are subject to the intricacies of wind change. They can be subject to, as well as generate, strong winds. The wind environment should be analyzed prior to construction since making changes after construction is very difficult and costly. scSTREAM can simulate accurate geometries by importing the numerical map (GIS format) for a specific building as well as the surrounding buildings.
Exhaust heat and Smoke
CFD can be used to analyze the diffusion of plant stack gas and the exhaust heat into the surrounding environment. CFD is used to predict the gas concentration at different altitudes. This analysis can be used to evaluate the efficiency of a specific cooling tower arrangement or the efficiency of an exterior air conditioning unit.
CFD is used to evaluate ventilation system performance. SC/Tetra is used when the analysis involves complicated shapes such as the inside and outlet of an air-conditioner. scSTREAM is used for the analysis of surrounding airflow and/or for simpler geometries.
A paint booth requires precise control of air flows similar to a clean room. Precise air flow ensures paint reaches the target part and is not washed away into the exhaust. scSTREAM can be used to simulate particles. This enables inclusion of coupling effects between the airflow and particles which ultimately determine where the particles will go.
Air flow around Bridge
Windy environments are induced in valley-shaped terrains. A wind analysis should be conducted whenever there is construction in these areas. scSTREAM can import terrain geography from map data and calculate wind pressures on buildings and bridges.
Water Flow over a Dam
scSTREAM and SC/Tetra can perform free surface analyses which calculate fluid surface shape. The free surface analysis can simulate water accumulation and flow over a dam.
Flow around a Water Gate
Using the moving object function, SC/Tetra can calculate the fluid flow field associated with closing down a water gate. This includes pressure fluctuations and the water surface elevation.
Analysis of Thermal Environment of a Data Center
In a data center where a large number of servers must be cooled adequately, it is vital to keep the room temperature at constant level. By conducting thermo-fluid analyses, it is possible to evaluate whether desgin parameters meet the requirement, such as air-conditioning performances, vent allocations, appropriate spacing between the servers.Button Text
Analysis of Air Flow inside Clean Room (Speed Vector and Concentration Distribution).
In a cleanroom, the number of floating particulates in the space is maintained below a certain level. Temperature, humidity, and pressure are also regulated. Using scSTREAM, it is possible to create models of particulates represented in diffusive species or particles and predict how air contaminants distribute and behave in the space.
Analysis of Car Exhaust Diffusion in an Expressway
Car exhaust from highway drifts over roadside barriers and diffuses into the surrounding space. It is possible to predict the effect on neighboring environment and residents by analyzing advective diffusion of exhaust gas and how wind may influence the flow.
Analysis of Humidity in Indoor Space Facilitated with Humidity Conditioner
Humidity conditioner can be facilitated to maintain comfortable indoor environment and dry wet laundry indoor on a rainy day. When a indoor humidity conditioner is used, room temperature rises due to latent heat generated and decreasing humidity level. Using scSTREAM, it is possible to account for such effects created by humidity conditioner and perform humidity analysis of indoor space.
Fluid flow analysis of an axial fan is challenging because the blade shape significantly affects performance. Accurate geometry representation and grid generation is critical. Starting from CAD data, SC/Tetra's automatic mesh generator can create the computational mesh in a matter of hours. In contrast, most conventional CFD software will require weeks to create the mesh. SC/Tetra simulates rotating blades using the rotating boundary (ALE) function. In addition, SC/Tetra perform a preliminary steady state analysis using only blade rotating forces.
SC/Tetra greatly reduces working hours for simulating a sirocco fan, as well as a propeller fan. A transient analysis using the ALE function (Arbitrary Lagrangian Eulerian for moving and/or rotating boundaries) can be used to provide more accurate details over and above a cursory steady state analysis.
A blower moves the working fluid with rotating blades similar to other fans. SC/Tetra can model both gases and liquids.
Air flow around Buildings
The shape and the number of blades greatly affect the performance of a turbofan. SC/Tetra can be used to evaluate several different cases in a short time because it is possible to build a model by changing only the rotating parts and its area.
The internal flow of a vortex blower, which can rotate in either direction, contains a highly complex flow that can only be effectly visualized using CFD. CFD is useful for making this complicated flow visible and enabling the user to understand basic flow structure and physics.
The computation of the fluid flow through fans and turbines tends to take a long time because of the transient phenomenon that occurs between the rotating and stationary components. However, SC/Tetra possesses convenient functions design to facilitate these analyses. These include the axial symmetric condition, periodic boundary conditions, and treating the rotating force as a rotating object instead of simulating the actual rotation. These functions can greatly reduce the calculation time while still accurately simulating the physics.
CFD analysis is also used for the analysis of the dye coating process. This process uniformly coats materials with a dye liquid (paint) using wall movement. The free surface condition is used at the liquid/air interface since the thickness of liquid is the parameter being calculated. CFD enables conducting parametric analyses to evaluate the effects of changing the velocity of the moving wall, wall roughness, viscosity and velocity of the liquid.
Chemical Vapor Deposition
CFD is used for Chemical Vapor Deposition (CVD) process analysis that is used to generate thin films such as silicon on printed circuit boards. SC/Tetra can handle a multiple-gas mixing analysis as well as a single carrier gas.
For a mixing tank that mixes multiple materials, SC/Tetra is used to evaluate the performance of the mixing blades and mixing tank pattern. scSTREAM can be used to evaluate mixing multiple materials. These tools can be applied to simulate a wider variety of chemical phenomena by using additional functions such as chemical reaction, particle tracking, and multi-phase flow along with the simple thermal/fluid analysis.