擴(kuò)散器涵道
13.擴(kuò)散器涵道進(jìn)口處的狀態(tài)與壓氣機(jī)出氣口處相同，即19，049磅。因此，假定擴(kuò)散器：
出口面積 (A)=205平方英寸 壓力 (P)=95磅／平方英寸(表值)
速度 (vJ)=368英尺／秒 質(zhì)量流量(w)=153磅／秒
燃燒室
14.燃燒室進(jìn)口處的狀態(tài)與擴(kuò)散器出口處相同，即21，235磅。
因此，假定燃燒室：
Thrust distribution
渦輪裝置
15.渦輪進(jìn)口處的狀態(tài)與燃燒室出口處相同，即55，417磅。
因此，假定渦輪：
……
=向前的推力-41，091磅這個(gè)負(fù)值意味著一個(gè)向后作用的力。
向前的總推力2，186磅
Combustion chambers
14. The conditions at the combustion chamber inlet are the same as the conditions at the diffuser outlet, i.e. 21,235 lb. Therefore, given that the combustion
chamber-
OUTLET Area Pressure Velocity Mass flow (A) (P) (vJ) (W) = = = = 580 sq.in. 93 lb. per sq.in. (gauge) 309 ft. per sec. 153 lb. per sec.
The thrust
WVJ
= (A xP) +. 21,235
g 153 x 309
= (580 x 93) +. 21,235
32 = 55,417 - 21,235 向前的總推力34，182磅
= 34,182 !b. of thrust in a forward direction.
Turbine assembly
15. The conditions at the turbine inlet are the same as the conditions at the combustion chamber outlet,
i.e. 55,417 lb.
Therefore given that the turbine--
OUTLET Area Pressure Velocity Mass flow (A) (P) (vJ) (W) = = = = 480 sq.in. 21 lb. per sq.in. (gauge) 888 ft. per sec. 153 lb. per sec.
The thrust
WVJ
= (A xP) +. 55,417
g 153 x 888
= (480 x 21) +. 55,417
32 = 14,326 - 55,417 = -41,091
This negative value means a force acting in a rearward direction.
Exhaust unit and jet pipe
16. The conditions at the inlet to the exhaust unit
are the same as the conditions at the turbine outlet,
i.e. 14,326 lb.
Therefore, given that the jet pipe--OUTLET Area (A) = 651 sq.in.
Pressure (P) = 21 lb. per sq.in.
(gauge) Velocity (vJ) = 643 ft. per sec. Mass flow (W) = 153 lb. per sec.
渦輪裝置
排氣裝置和噴管
16.排氣裝置進(jìn)口處的狀態(tài)與渦輪出口處相同，即14，326磅。因此，假定噴管：……
210
推進(jìn)噴管
17．推進(jìn)噴管進(jìn)口處的狀態(tài)與噴管出口處相同，即16，745磅。因此，假定推進(jìn)噴管：……
需要強(qiáng)調(diào)指出的是，這些是基率的計(jì)算，象空氣引氣的影響這類因素已忽略不計(jì)。
18.根據(jù)各項(xiàng)計(jì)算。向前的或正的載荷總數(shù)是57，836磅，向后的或負(fù)載荷的總數(shù)是46，678磅。因而總(總的或全部的)推力為11，158磅。
The thrust WVJ
= (A xP) +.14,326
g 153 x 643
= (651 x 21) +.14,326
32 = 16,745 - 14,326 向前的總推力2，419磅
= 2,419 lb. of thrust in a forward direction.
Propelling nozzle
outlet, i.e. 16,745 lb.
Therefore, given that the propelling nozzle--
17. The conditions at the inlet to the propelling 20. Although the momentum change of the gasnozzle are the same as the conditions at the jet pipe stream produces most of the thrust developed by the
OUTLET Area Pressure
Velocity Mass flow
(A)
= 332 sq.in.
(P)
= 6 lb. per sq.in.
(gauge) (vJ) = 1,917 ft. per sec.
(W)
= 153 lb. per sec.
Thrust distribution
The thrust WVJ
= (A xP) +.16,745
g 153 x 1,917
= (332 x 6) +.16,745
32
= 11,158 - 16,745
= 5,587lb. acting in a rearward direction.
向后總推力5，587磅
It is emphasized that these are basic calculations and such factors as the effect of air offtakes have been ignored.
18. Based on the individual calculations, the sum of the forward or positive loads is 57,836 lb. and the sum of the rearward or negative loads is 46,678 lb. Thus, the resultant (gross or total) thrust is 11,158 lb.
Engine
19. It will be of interest to calculate the thrust of the engine by considering the engine as a whole, as the resultant thrust should be equal to the sum of the individual gas loads previously calculated.
推進(jìn)噴管
WVJ
engine (momentum thrust = ), an additional
g thrust is produced when the engine operates with the propelling nozzle in a 'choked' condition (Part 6). This thrust results from the aerodynamic forces which are created by the gas stream and exert a pressure 動(dòng)量推力
across the exit area of the propelling nozzle (pressure thrust). Algebraically, this force is expressed as (P-P0) A.
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