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augmentation of heat transfer coefficients and pressure
drop during condensation of HFC-134a in a horizontal
tube at the presence of different twisted tape inserts was
carried out in [7]. The experiments were performed for a
plain tube and four tubes with twisted tapes inserts of 6,
9, 12 and 15 twist ratios. Similarly, the numerical and ex-
perimental investigations to understand convective heat
transfer from a single round pipe coiled in rectangular
pattern are presented in [8] where the studied heat ex-
changers were composed with inner and outer coils so
that the exterior flow is very similar to flow within tube-
bundles. The inner and outer coils of the heat exchangers
are in turn composed of bends and straight portions. The
investigation of the flow field and the heat transfer char-
acteristics of a shell-and-tube heat exchanger for the
cooling of syngas were carried out in [9] in which the
finite volume method based on FLUENT software and
the turbulence model was adopted for modeling turbulent
flow. The pressure drop, the temperature distribution and
the variation of local heat transfer were studied under the
effects of the syngas components and the operating pre-
ssure, and the effect of the arrangement of the baffles on
the heat transfer has been studied.
In this proposed work design, development & testing
of STHE is carried out. Along with the parameter con-
sidered in [1-8], vibration analysis is performed to opti-
mized unsupported span of tube by using HTRI software.
Detail overview on work carried out by researchers is
presented in Section 1, Section 2 & 3 states mechanics of
flow-induced vibration and the current problem defini-
tion & objective, details of STHE is given in Section 4.
Section 5 explores results of flow-induced vibration
analysis, final investigations and results are presented in
Section 6 and concluding remark is given in Section 7.
2. Mechanics of Flow-Induced Vibration
Failures of heat exchangers caused by flow-induced vibra-
tion are mainly in terms of the detriments of heat ex-
changer tubes. Generally, there are several main mecha-
nisms for flow-induced vibration in heat exchangers as
follows:
2.1. Vortex Shedding
When shell side fluid flows across heat exchanger tubes,
alternately varying Karman’s vortex streets will come
into being downstream of tubes, which generates periodic
changing exciting forces, which direction is perpendicular
to fluid flow, and results in vibration of tubes. When fre-
quency of vortex shedding is close or equal to the natural
frequency of tube, violent vibration will occur.
2.2. Fluid-Elastic Excitation
When fluid flows across tube bundle, due to the com-
plexity of flow condition, some certain tube in the bank
may take instant movement, thereby the flow field around
it changes and the equilibrium of forces on adjacent
tubes is broken, which makes tubes move and begin vi-
brating. When flow rate increases to a certain degree,
work of fluid elastic force on tube bundle will be larger
than the work consumed by damping action of tubes, then
amplitude of tube will increase rapidly and cause tubes to
collide with each other and be destructed.
2.3. Turbulent Buffeting
Turbulence is generated when shell side fluid, flow
through tube bundle. In the depth of in-line and interlac-
ing arrangement of tube bundle, with irregular turbulence
enlarging gradually, degree of turbulent pressure fluctua-
tion augments and has heat exchange tubes endure ran-
dom fluctuating acting forces. When basic frequency of