Pressure Losses across Multiple Fittings in Ventilation Ducts

Table 3

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

(a) Base case: Case 1

Re = 6.67×10^4	Case 1	Case 7		Case 8		Case 9
	Δ𝑃𝑆1	Δ𝑃𝑆1	Δ𝑃𝑆2	Δ𝑃𝑆1	Δ𝑃𝑆2	Δ𝑃𝑆1	Δ𝑃𝑆2
Pressure loss	72	66	66	64	185	54	588
Percentage decrease		8.3%		11.1%		25.0%

(b) Base case: Case 2

Re = 6.67×10^4	Case 2	Case 10		Case 11		Case 15
	Δ𝑃𝑆1	Δ𝑃𝑆1	Δ𝑃𝑆2	Δ𝑃𝑆1	Δ𝑃𝑆2	Δ𝑃𝑆1	Δ𝑃𝑆2	Δ𝑃𝑆3
Pressure loss	204	190	172	184	774	208	198	180
Percentage decrease		6.9%		9.8%		−2.0%	2.9%

(c) Base case: Case 3

Re = 6.67×10^4	Case 3	Case 12
	Δ𝑃𝑆1	Δ𝑃𝑆1	Δ𝑃𝑆2
Pressure loss	944	1030	750
Percentage decrease		−9.1%

(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		4.0%		5.3%	−2.7%