Turbulent flow identification across a heat exchanger

[octane]

Process engineers,
How can one know if the flow across the tubes of a heat exchanger is turbulent in nature?
Point me towards the reliable engineering calculations /equations to estimate that.

[tuan]

Reynolds number is the key here;
Once you calculate Re:
Re < 100 Laminar (very rare in shell side unless viscous fluid)
100 < Re < 1000 Transition
Re > 1000–2000 Turbulent crossflow
What is your intent?
Why are you worried about turbulence?

[octane]

I am asking with reference to the vibrations, and erosion happening on the inlet & exit of the heat exchanger piping elbows. All what our Process Engineers are saying is that there hasn't been any issue on their side.

[opo21]

You need to know:
There is NO universal Reynolds number limit for vibration
Turbulence is usually DESIRED - note this
The real limit is critical velocity vs actual velocity
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Therefore, you may need to look into:
Reducing baffle spacing
Increasing tube support
Using rod baffles / helical baffles
Adjusting tube pitch
Adding impingement plates
And all this during design phase
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Now in case you doubt anything not considered during design, all you need to is to approach design process engineer for heat exchanger, and piping /structure engineer for where you are experiencing vibrations.