Pressure Losses across Multiple Fittings in Ventilation Ducts

Table 4

Effect of upstream fitting(s) on pressure loss (Pa) across a downstream fitting.

(a) Base case: Case 1

Re = 6.67×10^4	Case 1	Case 7
	Δ𝑃𝑆1	Δ𝑃𝑆1	Δ𝑃𝑆2
Pressure loss	72	66	66
Percentage decrease			8.3%

(b) Base case: Case 2

Re = 6.67×10^4	Case 2	Case 8		Case 10		Case 15
	Δ𝑃𝑆1	Δ𝑃𝑆1	Δ𝑃𝑆2	Δ𝑃𝑆1	Δ𝑃𝑆2	Δ𝑃𝑆1	Δ𝑃𝑆2	Δ𝑃𝑆3
Pressure loss	204	64	185	190	172	208	198	180
Percentage decrease			9.3%		15.7%		2.9%	11.8%

(c) Base case: Case 3

Re = 6.67×10^4	Case 3	Case 9		Case 11		Case 12
	Δ𝑃𝑆1	Δ𝑃𝑆1	Δ𝑃𝑆2	Δ𝑃𝑆1	Δ𝑃𝑆2	Δ𝑃𝑆1	Δ𝑃𝑆2
Pressure loss	944	54	588	184	774	1030	750
Percentage decrease			37.7%		18.0%		20.6%

(d) Base case: Case 5

Re = 6.67×10^4	Case 5	Case 13		Case 14
	Δ𝑃𝑆1	Δ𝑃𝑆1	Δ𝑃𝑆2	Δ𝑃𝑆1	Δ𝑃𝑆2	Δ𝑃𝑆3
Pressure loss	150	144	150	142	154	118
Percentage decrease			0.0%		−2.7%	21.3%