Abstract
Three-dimensional laminar fluid flow and heat transfer over a four-row plate-fin and tube heat exchanger with electrohydrodynamic (EHD) wire electrodes are studied numerically. The effects of different electrode arrangements (square and diagonal), tube pitch arrangements (in-line and staggered) and applied voltage (VE=0–16 kV) are investigated in detail for the Reynolds number range (based on the fin spacing and frontal velocity) ranging from 100 to 1,000. It is found that the EHD enhancement is more effective for lower Re and higher applied voltage. The case of staggered tube pitch with square wire electrode arrangement gives the best heat transfer augmentation. For VE=16 kV and Re = 100, this study identifies a maximum improvement of 218% in the average Nusselt number and a reduction in fin area of 56% as compared that without EHD enhancement.
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Abbreviations
- C p :
-
Pressure drop coefficient, 2(pin − p)/ρ u 2in
- D :
-
Tube diameter (m)
- E :
-
Electric field strength (V m−1)
- f :
-
Fanning friction factor, 2·(p in − p)/ρ u 2in H/4L
- f 0 :
-
Fanning friction factor for flow without EHD
- F E :
-
EHD (N m−3)
- g :
-
Acceleration due to gravity (m s−2)
- h :
-
Heat transfer coefficient (W m−2 °C−1)
- \(\bar h\) :
-
Average heat transfer coefficient (W m−2°C−1)
- H :
-
Fin spacing (m)
- i :
-
Current density (A m−2)
- j :
-
Colburn factor \(\overline {{\text{Nu}}} /\left( {\operatorname{Re} \Pr ^{1/3} } \right)\)
- j 0 :
-
Colburn factor for flow without EHD
- k :
-
Thermal conductivity (W m−1°C−1)
- L :
-
Flow length (m)
- n :
-
Direction normal to the surface
- Nu:
-
Local Nusselt number, h·H/k
- \(\overline {{\text{Nu}}}\) :
-
Average Nusselt number, \(\bar h \cdot H/k\)
- P :
-
Pressure (Pa)
- Pr:
-
Prandtl number, ν/α
- q :
-
Electric charge density (Cm−3)
- Re:
-
Reynolds number, Uin·H/ν
- S L :
-
Tube pitch for longitudinal direction (m)
- S T :
-
Tube pitch for transverse direction (m)
- T w :
-
Wall temperature (K)
- T :
-
Temperature (K)
- T b :
-
Bulk mean temperature (K)
- T in :
-
Inlet temperature (K)
- U in :
-
Frontal velocity (m s−1)
- u :
-
Fluid velocity (m s−1)
- V :
-
Voltage (V)
- V E :
-
Voltage at wire electrode (V)
- X, Y, Z:
-
Coordinates
- α:
-
Thermal diffusivity (m2 s−1)
- ɛ:
-
Fluid permittivity (F m−1)
- σE:
-
Electrical conductivity ( m−1)
- ρ:
-
Fluid density (kg m−3)
- ν:
-
Kinematic viscosity (m2 s−1)
- μ:
-
Dynamic viscosity (N s m−1)
- Θ:
-
Dimensionless temperature, (T−Tin)/(T w −Tin)
- Θb:
-
Dimensionless bulk mean temperature, (Tb− Tin)/(Tw−Tin)
- 0:
-
Without electric field
- →:
-
vectors
References
Ishiguro H, Nagata S, Yabe A, Nariai H (1991) Augmentation of forced-convection heat transfer by applying electric fields to disturb flow near a wall. ASME J 3:25–31
Kulacki FA (1983) In: Kakac S (ed.), Augmentation of low reynolds number forced convection channel flow by electrostatic discharge, in low Reynolds number flow heat exchangers. Hemisphere, Washington, pp 753–782
Landau LD, Lifshitz EM (1963) Electrohydrodynamics of continuous media. Pergamon, New York
Mase GE (1970) Continuum mechanics. McGraw-Hill, New York
Nelson DA, Ohadi MM, Zia S, Whipple RL (1991) Electrostatic effects on heat transfer and pressure drop in cylindrical geometries. ASME J 3:33–39
Ogata J, Iwafuji Y, Shimada Y, Yamazaki T (1992) Boiling heat transfer enhancement in tube-bundle evaporators utilizing electric field effects. ASHRAE Trans 98(2): 435–444
Ohadi MM, Nelson DA, Zia S (1991) Heat transfer enhancement of laminar and turbulent pipe flow via corona discharge. Heat Mass Transfer J 4:1175–1187
Ohadi MM, Webber JM, Kim SW, Whipple RL (1991) Effect of humidity, temperature and pressure on corona discharge characteristics and heat transfer enhancements in a tube. ASME J 3:15–24
Ohadi MM, Faani M, Papar R, Rademacher R, Ng T (1992) EHD heat transfer enhancement of shell-side boiling heat transfer coefficients of R-123/Oil Mixture. ASHRAE Trans 98(2): 427–434
Owsenek BL, Seyed-Yagoobi J, Page RH (1995) Experimental investigation of corona wind heat transfer enhancement with a heated horizontal flat plat. Heat Transfer J 117:309–315
Pantaker SV (1981) A calculation procedure for two dimensional elliptic problem. Numeric Heat Transfer 4:409–426
Poulter R, Allen PHG (1986) Electrohydrodynamically augmented heat and mass transfer in the shell/tube heat exchanger. In: Proceedings of the 8th international heat transfer conference, San Francisco, pp 2963–2968
Tada Y, Takimoto A, Hayashi Y (1991) Heat transfer enhancement in a convective field by applying ionic wind. ASME J 3:9–14
Wangnippanto S, Tiansuwan J, Jiracheewanun S, Wang CC, Kiatsiriroat T (2001) Air side performance of thermosyphon heat exchanger in low reynolds number region with and without electric field. Energy Conserv Manage 43:1791–1800
Webb RL (1994) Principles of enhanced heat transfer. Wiley, New York
Yabe A (1991) Active heat transfer enhancement by applying electric fields. ASME J 3: xv-xxiii
Yabe A, Mori Y, Hijikata K (1978) EHD study of the corona wind between wire and plate electrode. AIAA J 16(4): 340–345
Yabe A, Mori Y, Hijikata K (1987) Heat transfer enhancement techniques utilizing electric fields. Heat Transfer High Technol Power Engineer: 394–405
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Lin, CW., Jang, JY. 3D Numerical heat transfer and fluid flow analysis in plate-fin and tube heat exchangers with electrohydrodynamic enhancement. Heat Mass Transfer 41, 583–593 (2005). https://doi.org/10.1007/s00231-004-0540-6
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DOI: https://doi.org/10.1007/s00231-004-0540-6