Abstract
The current 3-D numerical analysis explores the effect of combinations of rectangular winglet pairs (RWPs) having different attack angles (i.e. 5°, 15° and 25°) along a row of the tube array, on the performance of the fin and tube heat exchanger (FTHE). The considered airside Reynolds number Re ranges from 500 to 900. In total, six combinations of three attack angle vortex generators (VGs) have been numerically analysed namely 5°-15°-25°, 5°-25°-15°, 15°-5°-25°, 15°-25°-5°, 25°-5°-15° and 25°-15°-5°. The performance of the FTHE is represented by area goodness factor. The performance rankings of the FTHEs are also obtained by the MOORA method. Finally, 5°-25°-15° case provides the best thermal hydraulic performance for which heat transfer coefficient (h) is increased by 68.20% at Re = 500 and 81.78% at Re = 900, with a significant pressure drop penalty.
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Abbreviations
- A T :
-
total heat transfer surface area (m2)
- A min :
-
minimum flow area (m2)
- c p :
-
specific heat (J kg−1 K−1)
- D :
-
outer tube diameter (m)
- D h :
-
hydraulic diameter, Dh = 4AminL/AT
- f :
-
friction factor
- F p :
-
fin pitch (m)
- F t :
-
fin thickness (m)
- h :
-
air-side heat transfer coefficient (W m−2 K−1)
- H :
-
channel height (m)
- H w :
-
winglet height (m)
- j :
-
Colburn j-factor
- L :
-
flow length (m)
- m :
-
mass flow rate (kg/s)
- Nu :
-
average Nusselt number
- p :
-
pressure (Pa)
- P f :
-
fan power (W)
- Pr :
-
Prandtl number
- P l :
-
longitudinal tube pitch (m)
- P s :
-
span wise tube pitch (m)
- Q :
-
heat transfer capacity (W)
- Re :
-
air side Reynolds number
- St :
-
Stanton number
- T :
-
temperature (K)
- T out :
-
outlet temperature (K)
- T w :
-
wall temperature (K)
- \( \bar{T} \) :
-
bulk average temperature (K)
- T in :
-
inlet temperature (K)
- ∆T m :
-
mean value of temperature
- \( \bar{p} \) :
-
bulk average pressure (Pa)
- ∆p :
-
air side pressure drop (Pa)
- U :
-
free stream velocity (ms−1)
- u :
-
velocity in x-direction (ms−1)
- v :
-
velocity in y-direction (ms−1)
- V m :
-
mean velocity at Amin (m s−1)
- w :
-
velocity in z-direction (m s−1)
- μ :
-
dynamic viscosity (Pa.S)
- ρ :
-
density (kg m−3)
- λ :
-
thermal conductivity (W m−1K−1)
- η f :
-
fan efficiency
- FTHE:
-
finned tube heat exchanger
- MOORA:
-
multi-objective optimization on the basis of ratio analysis
- RWP:
-
rectangular winglet pair
- LVG:
-
longitudinal vortex generators
- CFD:
-
common flow down
- CFU:
-
common flow up
References
Jacobi A M and Shah R K 1995 Heat transfer surface enhancement through the use of longitudinal vortices: a review of recent progress. Experimental Thermal and Fluid Science 11: 295–309
Bendaoud A L, Ouzzane M, Aidoun Z and Galanis N 2011 A novel approach to study the performance of finned-tube heat exchangers under frosting conditions. Journal of Applied Fluid Mechanics 4: 9–20
Yoo S Y, Park D S and Chung M H 2002 Heat transfer enhancement for fin-tube heat exchanger using vortex generators. KSME International Journal 16: 109–115
Chu P, He Y L, Lei Y G, Tian L T and Li R 2009 Three-dimensional numerical study on fin-and-oval-tube heat exchanger with longitudinal vortex generators. Applied Thermal Engineering 29: 859–876
Huisseune H, Joen C T, Jaeger P, De Ameel B, Schampheleire S D and Paepe M D 2013 Influence of the louver and delta winglet geometry on the thermal hydraulic performance of a compound heat exchanger. International Journal of Heat and Mass Transfer 57: 58–72
Tiwari S, Maurya D and Eswaran V 2003 Heat transfer enhancement in cross-flow heat exchangers using oval tubes and multiple delta winglets. International Journal of Heat and Mass Transfer 46: 2841–2856
Leu J S, Wu Y H and Jang J Y 2004 Heat transfer and fluid flow analysis in plate-fin and tube heat exchangers with a pair of block shape vortex generators. International Journal of Heat and Mass Transfer 47: 4327–4338
Joardar A and Jacobi A M 2008 Heat transfer enhancement by winglet-type vortex generator arrays in compact plain-fin-and-tube heat exchangers. International Journal of Refrigeration 31: 87–97
Kumar A, Joshi J B, Nayak A K and Vijayan P K 2015 A review on the thermal hydraulic characteristics of the air-cooled heat exchangers in forced convection. Sādhanā 3(40): 673–755
Arshad H, Khushnood S, Nizam L A, Ahsan M A and Bhatti O G 2018 Effect of fin geometry on flow-induced vibration response of a finned tube in a tube bundle. Journal of Applied Fluid Mechanics 11(40): 1143–1152
Wu J M and Tao W Q 2008 Numerical study on laminar convection heat transfer in a rectangular channel with longitudinal vortex generator. Part A: Verification of field synergy principle. International Journal of Heat and Mass Transfer 51: 1179–1191
Lin C N, Liu Y W and Leu J S 2008 Heat transfer and fluid flow analysis for plate-fin and oval tube heat exchangers with vortex generators. Heat Transfer Engineering 29(7): 588–596
He Y L, Han H, Tao W Q and Zhang Y W 2012 Numerical study of heat-transfer enhancement by punched winglet-type vortex generator arrays in fin-and-tube heat exchangers. International Journal of Heat and Mass Transfer 55: 5449–5458
He Y L, Chu P, Tao W, Zhang Y W and Xie T 2013 Analysis of heat transfer and pressure drop for fin-and-tube heat exchangers with rectangular winglet-type vortex generators. Applied Thermal Engineering 61: 770–783
Zeeshan M, Hazarika S A, Nath S and Bhanja D 2017 Numerical investigation on the performance of fin and tube heat exchangers using rectangular vortex generators. AIP Conference Proceedings (1859): 020011
Zeeshan M, Nath S, Bhanja D and Das A 2018 Numerical investigation for the optimal placements of rectangular vortex generators for improved thermal performance of fin-and-tube heat exchangers. Applied Thermal Engineering 136: 589–601
Sinha A M, Chattopadhyay H, Iyengar A K and Biswas G 2016 Enhancement of heat transfer in a fin-tube heat exchanger using rectangular winglet type vortex generators. International Journal of Heat and Mass Transfer 101: 667–681
Sharma B, Bhushan G and Sachdeva G 2017 Effect of flow structure on heat transfer in compact heat exchanger by using finite thickness winglet at acute angle. Journal of Thermal Engineering 3(2): 1149–1162
Sarangi S K and Mishra D P 2017 Effect of winglet location on heat transfer of a fin and-tube heat exchanger. Applied Thermal Engineering 116: 528–540
Lin C N and Jhang J Y 2002 Conjugate heat transfer and fluid flow analysis in fin-tube heat exchangers with wave-type vortex generators. Journal Enhanced Heat Transfer 9: 123–136
Valentino M I, Tran L V, Ricklick M and Kapat J S 2012 A study of heat transfer augmentation for recuperative heat exchangers: comparison between three dimple geometries. Journal of Engineering for Gas Turbines and Power 134(072303): 1–9
Wang C C, Chen K Y, Liaw J S and Tseng C Y 2015 An experimental study of the air-side performance of fin-and-tube heat exchangers having plain, louver, and semi-dimple vortex generator configuration. International Journal of Heat and Mass Transfer 80: 281–287.
Gholami A A, Wahid M A and Mohammed H A 2014 Heat transfer enhancement and pressure drop for fin-and-tube compact heat exchangers with wavy rectangular winglet-type vortex generators. International Communications in Heat and Mass Transfer 54: 132–140
Oneissi M, Habchi C, Russeil S, Bougeard D and Lemenand T 2016 Novel design of delta winglet pair vortex generator for heat transfer enhancement. International Journal of Thermal Sciences 109: 1–9
Lu G and Zhou G 2016 Numerical simulation on performances of plane and curved winglet type vortex generator pairs with punched holes. International Journal of Heat and Mass Transfer 102: 679–690
Song K W, Xi Z P, Su M, Wang L C, Wu X and Wang L B 2017 Effect of geometric size of curved delta winglet vortex generators and tube pitch on heat transfer characteristics of fin-tube heat exchanger. Experimental Thermal and Fluid Science 82: 8–18
Zeeshan M, Nath S and Bhanja D 2017 Numerical study to predict optimal configuration of fin and tube compact heat exchanger with various tube shapes and spatial arrangements. Energy Conversion and Management 148: 737–752
Zeeshan M, Nath S and Bhanja D 2019 Determination of optimum winglet height of longitudinal vortex generators for the best thermo-hydraulic performance of compact heat exchangers. Journal of Mechanical Science and Technology 33(9): 4529–4534
Sun L and Zhang C L 2014 Evaluation of elliptical finned-tube heat exchanger performance using CFD and response surface methodology. International Journal of Thermal Sciences 75: 45–53
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Zeeshan, M., Nath, S. & Bhanja, D. Numerical investigation to predict optimum attack angle combination of longitudinal vortex generators in compact heat exchangers for thermo-hydraulic heightened performance. Sādhanā 44, 241 (2019). https://doi.org/10.1007/s12046-019-1219-5
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DOI: https://doi.org/10.1007/s12046-019-1219-5