1. Introduction
Turbulators are widely used in process industries and many methods have been proposed to improve the performance. One of these methods is the use of short conical swirlers (SCS) in conjunction with a swirling flow field generated by the flow of a single phase. SCSs are designed to generate radial and tangential acceleration locations in a single phase flow field. This type of turbulator can be used for a variety of applications, such as flow control, turbulence enhancement and heat transfer enhancement.
2. Design
The main characteristics of SCS are their small diameter, a small length and their conical geometry. The design parameters for SCS are selected according to the desired flow characteristics. The different design parameters for SCS can be classified based on their respective roles in the process. The main design parameters for SCS are diameter, length of conical section, number of conical sections and angle of cone.
Diameter is an important SCS design parameter. It determines the size of the turbulator per unit length. Generally, smaller diameters are preferred over larger diameters as they provide higher fluid accelerations and create a more intense swirling pattern.
Length of the conical section is another important SCS design parameter. The length of the conical section determines the amount of swirl that can be created. In general, shorter length is preferred over a longer length as it helps in avoiding boundary layer separation which can lead to lower performances.
The number of conical sections per unit length is another important SCS design parameter. Increasing the number of conical sections reduces the size of the turbulator and allows for more intense swirls. However, too many sections can reduce the turbulence intensity and lead to poorer performances.
The angle of cone is an important SCS design parameter. It is determined by the desired swirl intensity and velocity. Generally, higher angles of cone are preferred over lower angles as they provide higher velocities and swirl intensity. The angle of cone also affects the location of the radial and tangential acceleration locations in the flow field.
3. Modeling
To model the effect of SCS on a single phase flow field, Computational Fluid Dynamics (CFD) has been used. CFD is a powerful tool to study the effect of different designs of SCS on the flow field. With the help of CFD, the fluid flow field can be studied for different designs of SCS in detail and can help in choosing an appropriate design for a specific application.
The CFD model is used to simulate the velocity and turbulence fields generated by SCS. The turbulence field is described by the k-ε turbulence model and the boundary conditions are set using the boundary conditions from the computational domain. Pressure boundary conditions are set to account for the variation in pressure between the inlet and outlet ports of the computational domain.
The CFD model is used to study the effect of SCS design on the velocity and turbulence fields of the CFD model. The CFD model is also used to study the effect of SCS design on the pressure field of the CFD model. The CFD model is used to study the effect of SCS on the flow field over a range of Reynolds numbers.
4. Performance
The performance of a SCS is assessed based on three performance parameters: the pressure drop across the turbulator, flow uniformity and turbulence intensity.
The pressure drop across the turbulator is an important performance parameter as it quantifies the amount of energy loss in the flow due to the presence of the turbulator. Generally, a lower pressure drop is preferred over a higher pressure drop as it indicates higher efficiency in the process.
Flow uniformity is a measure of how the flow field is distributed across the turbulator. A higher flow uniformity is preferred to a lower one as it indicates a more even flow distribution across the turbulator.
Turbulence intensity is a measure of the magnitude of turbulence in the flow. A higher turbulence intensity is desired over a lower one as it enhances the heat transfer and facilitates better mixing in the process.
5. Conclusion
Short conical swirlers are designed to generate radial and tangential acceleration locations in a single phase flow field. Different design parameters such as diameter, length and number of conical sections per unit length, and angle of cone are used to determine the performance of SCS in a single phase flow field. Computational Fluid Dynamics (CFD) has been used to study the effect of SCS design on pressure drop, flow uniformity and turbulence intensity.
Overall, short conical swirlers can be effectively used in process industries to enhance heat transfer, flow control, and turbulence intensity without compromising any performance parameters.
