Conjugate Natural Convection: A Study of Optimum Fluid Flow and Heat Transfer in Eccentric Annular Channels

Table 1

Summary of mesh-independence test in eccentric annuls and cylinder walls.

Parameters/mesh size		Eccentric annular channel mesh (N × M)						Mesh of inner and outer cylinder walls (NSI & NSO)
		20 × 20	20 × 25	25 × 25	25 × 30	30 × 25	30 × 30	20 & 20	20 & 25	25 & 25	25 & 30	30 & 25	30 & 30
	Value	2.94404	2.94400	2.94622	2.94627	2.94907	2.94908	2.94671	2.94795	2.94731	2.94910	2.94616	2.94793
	% err.	0.171	0.172	0.097	0.095	0.000		0.041	0.001	0.021	0.040	0.060
	Value	−1.46824	−1.46820	−1.46707	−1.46704	−1.46561	−1.46560	−1.46701	−1.46740	−1.46689	−1.46753	−1.46610	−1.46672
	% err.	0.180	0.178	0.101	0.098	0.001		0.020	0.046	0.012	0.055	0.042
	Value	5.05493	5.05466	5.05068	5.05061	5.04894	5.04884	5.04889	5.04856	5.04570	5.04543	5.04101	5.04076
	% err.	0.120	0.115	0.036	0.035	0.002		0.161	0.155	0.098	0.093	0.005
	Value	3.51597	3.51608	3.52096	3.52103	3.52393	3.52401	3.52339	3.52670	3.52723	3.53203	3.52800	3.53273
	% err.	0.228	0.225	0.087	0.085	0.002		0.264	0.171	0.156	0.020	0.134
	Value	0.41759	0.41757	0.41667	0.41665	0.41590	0.41589	0.41636	0.41608	0.41588	0.41549	0.41556	0.41518
	% err.	0.409	0.403	0.187	0.183	0.003		0.284	0.217	0.169	0.075	0.092
Time (min.)	Value	4.90300	7.64284	13.01452	21.75052	22.52500	35.34551	14.86751	15.149	16.57467	17.11302	18.23717	18.67467
	% ratio	13.872	21.623	36.821	61.537	63.728		79.613	81.122	88.755	91.638	97.657