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Stefan Hoffmann, M.Sc.
2021-08-31

FAQ 005069 | What is the meaning of the difference in the checksum of drag forces?

FAQ|005069

Question:
What is the meaning of the difference in the checksum of drag forces?

Answer:
After a successful calculation, the checksums of drag forces are displayed on the original model and on the simplified model in RWIND Simulation in the legend of the graphic window.  They represent the resultants of the wind load in the global directions X, Y, and Z.
You can use it to compare the drag forces acting on the original model and the simplified model.
The simplified mesh is a special mesh that envelops the original model, and thus defines the model boundary.

If there are significant differences between the checksums, you should increase the level of detail in the Edit Model dialog box for a more refined, simplified model.

FAQ 005069 | What does the difference in the checksum of the drag forces mean?
FAQ 005069 | Checksum - Level of Detail 0
FAQ 005069 | What is the meaning of the difference in the checksum of drag forces?
FAQ 005069 | Checksum - Level of Detail 2

However, if there are any differences, please note that any closed openings may also have an influence on the checksums.

FAQ 005069 | What is the meaning of the difference in the checksum of drag forces?
FAQ 005069 | Checksum - Closed Opening
FAQ 005069 | What is the meaning of the difference in the checksum of drag forces?
FAQ 005069 | Checksum with Opening
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Figure 1: Validation Example Model
Creating a validation example for Computational Fluid Dynamics (CFD) is a critical step in ensuring the accuracy and reliability of simulation results. This process involves comparing the outcomes of CFD simulations with experimental or analytical data from real-world scenarios. The objective is to establish that the CFD model can faithfully replicate the physical phenomena it is intended to simulate. This guide outlines the essential steps in developing a validation example for CFD simulation, from selecting a suitable physical scenario to analyzing and comparing the results. By meticulously following these steps, engineers and researchers can enhance the credibility of their CFD models, paving the way for their effective application in diverse fields such as aerodynamics, aerospace, and environmental studies.
Figure 1: The Effect of the Wind Direction
Wind direction plays a crucial role in shaping the outcomes of Computational Fluid Dynamics (CFD) simulations and the structural design of buildings and infrastructures. It is a determining factor in assessing how wind forces interact with structures, influencing the distribution of wind pressures, and consequently, the structural responses. Understanding the impact of wind direction is essential for developing designs that can withstand varying wind forces, ensuring the safety and durability of structures. Simplified, the wind direction helps in fine-tuning CFD simulations and guiding structural design principles for optimal performance and resilience against wind-induced effects.
Figure 1: Wind Simulation on a Modern City Using RWIND
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Since wind on laterally open structures is not addressed in the Eurocode, the 4 cases of the German DIN 1055, Part 4 are referenced.
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Frequently Asked Questions (FAQ)
What is the difference between the RANS, URANS, and DDES turbulence models?
Is there an option to export the results of drag forces of all zones from RWIND in a table?
When exporting my model from RFEM to RWIND, I get the message "Warning No. 7731 | Reading of logger file failed." What can I do to start the simulation in RWIND?
How can I consider various wind profiles for various wind directions?
Is it possible to use load transfer surfaces in RFEM 6 for wind load generation using RWIND?
What is the meaning of the difference in the checksum of drag forces?
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