FLUID STRUCTURAL InTERACTION
PIPING ENGINEERING AND PIPING DESIGN
This study is for educational purposes only. No commercial purposes intended.
Embedded Files
PIPE SUPPORT LOAD
This is a continuation of determining the exact pipe support to be designed in 6" schedule 80 to include the fluid dynamics and static structural loads on vertical pipe with bend transporting a propylene glycol to reactor. We will determine the total force to hold the bend in place or the vertical displacement of pipe (if there is any significant force acting on it). Since our operating temperature is not that high, we will not be adding a conjugate heat transfer solution to analyze our system.
MODAL ANALYSIS
From the chart below for natural frequency, the highest contributing factor for displacement is along Y direction but the effective mass and ratio of effective mass to total max are at shifting along Z-direction.
SYSTEM COUPLING
Performance Timer for 310 iterations on 8 compute nodes
Average wall-clock time per iteration: 0.168 sec
Global reductions per iteration: 196 ops
Global reductions time per iteration: 0.000 sec (0.0%)
Message count per iteration: 12814 messages
Data transfer per iteration: 8.093 MB
LE solves per iteration: 9 solves
LE wall-clock time per iteration: 0.101 sec (60.2%)
LE global solves per iteration: 9 solves
LE global wall-clock time per iteration: 0.001 sec (0.6%)
LE global matrix maximum size: 114
AMG cycles per iteration: 11.832 cycles
Relaxation sweeps per iteration: 1548 sweeps
Relaxation exchanges per iteration: 0 exchanges
LE early protections (stall) per iteration: 0.000 times
LE early protections (divergence) per iteration: 0.000 times
Total SVARS touched: 411
Time-step updates per iteration: 0.06 updates
Time-step wall-clock time per iteration: 0.023 sec (13.8%)
Total wall-clock time: 52.104 sec
total reaction force
Total reaction force induced by static stress and fluid velocity which can be used to accurately design the pipe support in this segment excluding the effect of thermal expansion which is negligible based on operating conditions. NOTE: Update the boundary conditions based on the full throttle settings of control valve downstream and recalculate the results.
pre-SENSIBILITY ANALYSIS
Design points where we vary the pipe sizes using short and long radius elbow while maintaining the inlet pressure with varying inlet velocity to find corresponding volumetric metric flow at the outlet for fluid dynamic analysis. Note that the negative values of volume flow rate indicate that mass leaving the system and not the flow direction. For simplicity and to reduce computational time, only two desired variables were chosen but it can be expanded to multiple desired factors of fluid dynamics, heat transfer and structural analysis.
Setting the constraint of the volumetric flow rate and setting of objective to minimize the velocity at the inlet while maintaining our flow rate desired range. Although we can compute the above desired output manually using Darcy-Weisbach or Hagen-Poisuille equations the geometries can be complicated which may require iterative computations, this feature can be useful without manually changing the geometry every set of parameters as shown above.
Note that the biggest factor of erosion is the fluid velocity affecting the intrados and extrados of the elbow. Check the statistics section for the details of optimization analysis. Q.E.D.
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