Pipe with Twisted Tape Inserts Heat Transfer, Validation

Heat Transfer in Pipe with Twisted Tape Inserts, Paper CFD Validation, ANSYS Fluent CFD Simulation

The problem simulates heat transfer within a tube with a twisted strip using ANSYS Fluent software. The simulation process is based on the data in the reference article “Analysis of Heat Transfer in Pipe with Twisted Tape Inserts.” The results are compared with the results in the paper and validated.

The model is related to a tube inside which a twisted tape with a certain screw pitch is placed. The present model is designed in three dimensions using Design Modeler software.

The model consists of a tube with a diameter of 0.022 m and a length of 2.2 m, which in its interior has a twisted tape with a screw pitch equal to 0.110 m. Therefore, the ratio of the tape screw pitch to the pipe diameter is equal to 5.

The meshing has been done using ANSYS Meshing software, and the mesh type is unstructured. The element number is 476442.

Methodology

The fluid flowing inside this pipe is water with Reynolds equal to 800; as a result, the flow velocity of the incoming water is equal to 0.0365 m/s. Also, the inlet water flow temperature to the pipe is equal to 298.15 K, and the pipe wall is under a constant heat flux equal to 5725 W/m2.

The strip inside the pipe is thermally insulated and is solely responsible for affecting the amount of heat transfer from the wall of the pipe to the mass of fluid flowing inside the pipe.

Conclusion

This work aims to investigate the amount of Nusselt number on the pipe wall. So, at the end of the solution process, the value of the Nusselt number is obtained on the pipe wall.

This value was obtained when the Reynolds value of the flow is equal to 800, and the ratio of the pitch of the twisted strip to the diameter of the pipe is equal to 5.

Calculating the Nusselt value requires the correct reference values; So that in the present model, the characteristic length is equal to the diameter of the pipe, i.e., 0.022 m, and the reference temperature is equal to the bulk temperature of the fluid inside the pipe, which is equivalent to 306.7147 K.

The comparisons of the results of the present CFD simulation with the results of the article and the validation of the results have been done using the diagram of Figure 2 of the reference paper.

Also at the end, three-dimensional contours related to pressure, temperature, and velocity as well as three-dimensional path lines are obtained.