Five Engineering Applications of Computational Fluid Dynamics
Engineering firms are under constant pressure to deliver. Products must be manufactured faster and the demanded quality keeps on rising. For the producers, enhanced productivity is the only way out, but this can be a challenge to achieve. Only the most innovative companies survive in the fiercely competitive environment. Are you wondering how engineering firms manage to meet tight deadlines and quality requirements without running out of business?
Engineering applications of computational fluid dynamics is one of the secrets. Making CFD a key part of the initial design process can be helpful in minimizing unsuitable products. A lot of money can be saved in the process. That’s why CFD modeling is popular in engineering applications, including the following five.
Designing a power plant presents many challenges ranging from tough environmental conditions to uncertainty of future energy demands. Designers must consider these critical requirements in the design of power plant equipment. Owing to all the uncertainties that surround power plant design, CFD modeling is at the center of the design process.
In addition to the application of CFD modeling during the design phases, these technics are also applicable in maintenance, especially concerning cooling water systems characteristics. Scour studies, Physical modeling tests, Dispersion studies and related activities are done using CFD modeling.
At ARANER, CFD modeling is instrumental in power augmentation using turbine inlet air cooling (TIAC). During the modification of the filter house, ARANER uses Computational Fluid Dynamics (CFD) analysis. This system allows efficient simulation of airflow through the entire turbine system.
Fig 1: Detailed Analysis of the Filter House Modification
Air distribution and thermodynamical behaviour in the heat rejection by means of cooling towers in a district cooling plants
The performance of heat rejection equipment, such as cooling towers, depends not only on their internal thermodynamical behavior but also on the external aerodynamics. The actual integration of modern cooling plants as part of metropolis skylines requires the analysis of the thermo-fluid dynamic impact of adjacent buildings on the cooling towers.
The computational modeling of these cases is complex and involves important challenges:
- Different problem scales: Large domains including the buildings of a district in combination with accurate details of internal flow in cooling towers.
- Complex behavior of humid air.
The application of CFD to these cases enables the characterization of the internal heat transfer and the external behavior of the humid air. This facilitates the optimization of cooling tower designs and the reduction of recirculation.
TES Design in District Cooling
District cooling is an important and thriving solution in hot humid areas, especially the Middle East. For reliability purposes, district cooling systems go hand in hand with thermal energy storage (TES).
TES tank is a thermal accumulator for cooling produced during off-peak time. TES helps reduce the operational cost and the required capacity of the district cooling plant. The chilled water from TES tanks supplements the chiller capacity, covering for high demands instances, chiller restart periods, and power failure.
TES is available in both modes namely partial storage and full storage. The TES tank features two sets of water distribution; one at the bottom and another at the top. Separating the two layers is a non-physical boundary layer – thermocline. The thermocline is central to TES tank design because its size is directly proportional to the storage capacity and system efficiency.
Fig 2: TES Tank Showing Temperature Profile
For reliability, simplicity and low cost reasons, natural stratification is the most popular option. Gravity separates the water, with the warmer (less dense) water settling at the top and the colder (denser) water at the bottom. The performance of this separation layer is mainly defined by the fluid flow generated by the diffusers and defines the efficiency of the TES system. That is where computational fluid dynamics modeling comes in. ARANER uses this tool to predict heat transfer to the finest detail.
Engineers at ARANER consider the following parameters in the design process:
- Diffuser type
- Aspect ratio
- Flow rate
- Diffuser size
- Chilled water temperature
- Warm water temperature
Optimization of refrigeration equipment
Refrigeration equipment uses different fluids in its operation. However, the behavior of these working fluids must be studied and controlled in order to avoid that their interactions could affect the performance of the system.
One of these interactions is the one observed at the discharge of the compressor of cooling units between the refrigerant vapour and the oil of the compressor. Since the fluids are present in different phases, the accurate CFD simulation and the optimization of oil separators involve the implementation of complex multi-phase computational models.
Prevention of Cavitation
Every engineer knows the dangers posed by cavitation, the damaging phenomena caused by liquids under varying pressures. Those working with pumps understand the herculean task of troubleshooting this problem. While the damage caused by cavitation is gradual, detecting the problem using common methods is usually not helpful. For instance, instruments that measure noise and vibrations may not detect cavitation problem due to accuracy challenges.
CFD for cavitation simulation enables engineers to predict to the tiniest level and achieve the highest levels of longevity, safety and flexibility.
Before the discovery of simulation, solving most practical engineering problems was expensive and treacherous. Product failures and the ensuing reputation damage due to numerous product recalls affected business in many ways. Enter CFD modeling and engineering applications of computational fluid dynamics are possible in virtually any conceivable environment.
How are you using solutions such as the above computational fluid dynamics in five engineering industries? ARANER has successfully used the tool for TES designs in district cooling application. Check out this eBook for more on this design process.