The effect of a permanent magnet on ventilation of an air duct through compost has been investigated numerically. Some composts yield heat over $60°C$ in the fermentation process. This exothermic reaction produces a considerable amount of heat, which could be a potential heating source. Fermentation reaction requires ventilation, sufficient supply of oxygen, and exhaust of metabolized diamagnetic carbon dioxide gas. Continuous and forced air supply is more efficient rather than the conventional manual turn or stirring as ventilation means. In magneto-aero-dynamics, the magnetizing force acting on a paramagnetic oxygen gas is applied to enhance air flow, heat, and mass transfer. In our research, the enhancement of the air flow through air ducts of various sizes has been numerically investigated by applying a permanent magnet on an air duct. Numerical results show that a permanent magnet enhances the air flow, where we obtained a maximum inlet air velocity $(uin)$ of $6.24×10−2 m/s$. The application of a permanent magnet to an air duct is useful for compost heating system, a promising alternative energy system.

1.
Alexander
,
M.
, 1994,
,
,
San Diego, CA
.
2.
Fronk
,
B. M.
,
Neal
,
R.
, and
Garimella
,
S.
, 2010, “
Evolution of the Transition to a World Driven by Renewable Energy
,”
ASME J. Energy Resour. Technol.
0195-0738,
132
(
2
), p.
021009
.
3.
Yukawa
,
H.
, 2006,
Technology of Biomass Energy
,
CMC
,
Tokyo, Japan
.
4.
Kimura
,
T.
, 2003,
Composting of Biomass Resources
,
CMC
,
Tokyo, Japan
.
5.
Palmisano
,
A. C.
, and
Barlaz
,
M. A.
, 1996,
Microbiology of Solid Waste
,
CRC
,
Boca Raton, FL
.
6.
Haque
,
M. F.
,
Arajs
,
S.
,
Moyer
,
C. A.
,
Anderson
,
E. E.
, and
Blums
,
E.
, 1988, “
Effect of Electric and Magnetic Fields on the Convective Heat Transfer in Gaseous O2 and N2O
,”
J. Appl. Phys.
0021-8979,
63
(
8
), pp.
3561
3562
.
7.
Braithwaite
,
D.
,
Beaugnon
,
E.
, and
Tournier
,
R.
, 1991, “
Magnetically Controlled Convection in a Paramagnetic Fluid
,”
Nature (London)
0028-0836,
354
, pp.
134
136
.
8.
Pauling
,
L.
,
Wood
,
R. E.
, and
Sturdivant
,
J. H.
, 1946, “
An Instrument for Determining the Partial Pressure of Oxygen in a Gas
,”
J. Am. Chem. Soc.
0002-7863,
68
, pp.
795
798
.
9.
Uetake
,
H.
,
Hirota
,
N.
,
Nakagawa
,
J.
,
Ikezoe
,
Y.
, and
Kitazawa
,
K.
, 2000, “
Thermal Convection Control by Gradient Magnetic Field
,”
J. Appl. Phys.
0021-8979,
87
(
9
), pp.
6310
6312
.
10.
Carruthers
,
J. R.
, and
Wolfe
,
R.
, 1968, “
Magnetothermal Convection in Insulating Paramagnetic Fluids
,”
J. Appl. Phys.
0021-8979,
39
(
12
), pp.
5718
5722
.
11.
Ikezoe
,
Y.
,
Hirota
,
N.
,
Nakagawa
,
J.
, and
Kitazawa
,
K.
, 1998, “
Making Water Levitate
,”
Nature (London)
0028-0836,
393
, pp.
749
750
.
12.
Ruan
,
X.
,
Takeshima
,
M.
,
Wakayama
,
N. I.
,
Song
,
X.
, and
Yamamoto
,
F.
, 2001, “
Particle Image Velocimetry Investigation of N2-Air Convection Induced by Magnetic Fields
,”
J. Appl. Phys.
0021-8979,
40
, pp.
L648
L650
.
13.
,
E.
,
Shinoda
,
M.
,
Yamashita
,
H.
, and
Kitagawa
,
K.
, 2003, “
Experimental and Numerical Analyses of Magnetic Effect on OH Radical Distribution in a Hydrogen-Oxygen Diffusion Flame
,”
Combust. Flame
0010-2180,
135
, pp.
365
379
.
14.
Weppen
,
P.
, 2002, “
Determining Compost Maturity: Evaluation of Analytical Properties
,”
Compost. Sci. Util.
1065-657X,
10
(
1
), pp.
6
15
.
15.
Klejment
,
E.
, and
Rosinski
,
M.
, 2008, “
Testing of Thermal Properties of Compost From Municipal Waste With a View to Using It As a Renewable, Low Temperature Heat Source
,”
Bioresour. Technol.
0960-8524,
99
, pp.
8850
8855
.
16.
Tagawa
,
T.
,
Shigematsu
,
R.
, and
Ozoe
,
H.
, 2002, “
Magnetizing Force Modeled and Numerically Solved for Natural Convection of Air in a Cubic Enclosure: Effect of the Direction of the Magnetic Field
,”
Int. J. Heat Mass Transfer
0017-9310,
45
, pp.
267
277
.
17.
Weast
,
R. C.
,
Astle
,
M. J.
, and
Beyer
,
W. H.
, 1987,
CRC Handbook of Chemistry and Physics
,
CRC
,
Boca Raton, FL
.
19.
Patankar
,
S. V.
, 1980,
Numerical Heat Transfer and Fluid Flow
,
Hemisphere
,
Washington, DC
.
20.
Patankar
,
S. V.
, 1981, “
A Calculation Procedure for Two-Dimensional Elliptic Situations
,”
Numer. Heat Transfer
0149-5720,
4
, pp.
409
425
.
21.
Lu
,
S. S.
, and
Ozoe
,
H.
, 2006, “
Application of Multiple Magnetic Coils to Drive the Air Flow in a Long Pipe
,”
Int. J. Heat Mass Transfer
0017-9310,
49
, pp.
4536
4542
.