A andsingle phaseInteresting findings2.2.1.2 Shape and sizeLots of

A review of the literature reveals that numerous investigators have studied convective heattransfer subjected to vibration numerically, analytically and experimentally, in a variation ofconfigurations. Variables which effects heat transfer such as heat flux/temperature gradient,fluid as coolant(single or multiphase), shape, size, and orientation of enclosure and heatersubjected to heat load and on the other hand variables as direction, amplitude and frequencysubjected to vibrational load have been studied for both like natural and forced convectionheat transfer.The convective heat transfer with external vibration has been considerable interest formdecades. As per available literature in this particular field, it can be classified into threedifferent categories. In the first category, submerged heating surface oscillates but fluidremains stationary whereas in the second category, fluid vibrates and heating surface isstationary. Both techniques have the same objective of creating an oscillating relativevelocity between the heated surface and the adjacent fluid medium. However, in thirdcategory the fluid and the heated surface both are imposed to the vibration simultaneouslywhich has a number of practical applications. Pak at el.1972In the convective heat transfer flow, the magnitude of resulting flow velocities and themixing speed depend on the fluid properties, shape and size of enclosure and Rayleighnumber when the tank is stationary Road and Fadda 1997. Factors affecting the heat transfer under vibration2.2.1.1 Effect of Heat flux/ Rayleigh numberThe heat transfer increases with increase in heat flux or Rayleigh number. Few literatureshad described the effect of heat flux (R. E. Forbes et al. 1970), (H. K. Pak et al. 1972),(Tajik et al. 2013). Generally researchers described heat load in terms of non-dimensionalRayleigh number ( FU and SHIEH 1992, 1993), ( Khallouf et al. 1995), (FERGUSON andLILLELEHT 1996), (Khaled and Vafai 2004), (Khaled and Vafai 2004), (Fu and Huang2006), (Chang and Alexander 2007), (Himeno et. al. 2008, 2009, 2010 & 2011).ReferencesR. E. Forbes et al.1970H. K. Pak et al.(1972)Tajik et al. 2013Heat flux/Rayleighnumber taken18° F to 62° F10° F to 100° F40,60 and 80 WWorking fluid andphasedistilled water andsingle phasedistilled water andsingle phasedistilled water andsingle phaseInteresting findings2.2.1.2 Shape and sizeLots of studies had done on convective heat transfer under vibration in rectangular orcylindrical tanks with submerged heat source (H. K. Pak et al. 1972) and whereas group ofresearchers studied on heat transfer under vibration in rectangular differential heated cavitiesfilled with single(R. E. Forbes et al. 1970), (FU and SHIEH 1992, 1993), (Khallouf et al.1995), (Khaled and Vafai 2004), (Fu and Huang 2006) or two phase fluids, (Y.K. Oh et al.2002), (Chang and Alexander 2007), (Himeno et al. 2008, 2009, 2010, 2011). Effect ofaspect ratio of experimental cavity filled with water as working fluid investigated by (R. E.Forbes et al. 1970 and they reported that heat transfer increases with aspect ratio decrease.Khallouf et al. 1995 also reported the effect of cavity aspect ratio which filled with air on theheat transfer numerically. They also claimed heat transfer affected by aspect ratio of cavity.2.2.1.3 GravityLiterature reveals that effect of gravity in the study of heat transfer under vibration haskey role especially in the aerospace field. When the gravity consider zero and heat transferoccur due to vibration only, it is called thermo vibrational convection heat transfer. Fuel tanksin spacecraft with external vibration are important for evaluating the effect of the unavoidablevibrations of satellites and spacecraft mechanical structures on two phase fluid systems andfew literatures are available as Heat transfer is affected by liquid sloshing in propellant tankfor space satellite as claimed by Himeno et al. 2008, 2010, and 2011. Thermo convectiveflows induced by vibrations in reduced gravity field also studied to predict the behaviour ofoperated fluid use in spacecraft by Shevtsova et al. 2008, 2010. Khallouf et al. 1995 alsostudied thermo vibrational convection heat transfer as well as aspect ratio of cavity.2.2.1.4 Direction, amplitude, vibrational acceleration and frequencyAs literatures reveals, vibration was applied in wide range of frequency and accelerationamplitude as sinusoidal (Klaczak 1997), (Liu et al. 2017) or in terms of ultrasound inducedvibration. When UV induced vibration applied in the fluid system, it creates majorly twoeffects: acoustic cavitation and acoustic streaming which responsible of change in the rate ofheat transfer Tajik et al. 2013, Y.K. Oh et al. 2002. Direction at which vibration applied isalso a concerned. Parallel to gravity or vertical direction had taken by various researchers fordifferent fluids (R. E. Forbes et al. 1970), (H. K. Pak et al.1972), ( FU and SHIEH 1992,1993), ( Khallouf et al. 1995), (FERGUSON and LILLELEHT 1996), (Khaled and Vafai2004) and perpendicular to gravity or lateral direction has also considered in manyliteratures (Khaled and Vafai 2004), (Fu and Huang 2006), (Chang and Alexander 2007),(Himeno et. al. 2008, 2009, 2010 & 2011). The disturbances in the Nusselt number are moreprominent in the case of horizontal vibration as compared to the vertical vibration Khaledand Vafai 2004.Vibrational acceleration is main parameter for studying the heat transfer in the fluidsubjected to vibration.

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