If ( 0.8 ≤ f_w/f_n ≤ 1.2 ), redesign required:
The Reynolds number (Re) is a dimensionless quantity that characterizes the nature of fluid flow around the thermowell. It is calculated using the following formula: thermowell wake frequency calculation
A is a specialized engineering analysis used to ensure that a thermowell—the protective sleeve for a temperature sensor—can withstand the dynamic and static forces of a flowing process fluid. This calculation is critical for preventing vortex-induced vibration (VIV) , which is the primary cause of thermowell fatigue and catastrophic failure. If ( 0
[ f_w = \fracSt \cdot Vd_tip = \frac0.21 \times 50.025 = 42 \text Hz ] [ f_w = \fracSt \cdot Vd_tip = \frac0
$$f = \fracSt vD$$
The calculated wake frequency should be evaluated in the context of the thermowell design and operating conditions. If the wake frequency is too high, it may indicate a potential vibration problem.
A thermowell is a pressure-tight receptacle inserted into a process pipe or vessel to protect a temperature sensor (e.g., RTD, thermocouple) from corrosive, high-pressure, or high-velocity fluids. When fluid flows past a thermowell, alternating vortices shed from its downstream side—a phenomenon known as or a Kármán vortex street .