【正文】 h at who, also don39。 now want anything, for fear that others know, or like to lose the same. 9, the heart move, everything in the world is followed by birth, Rangrang, important thing is often the most difficult to open one39。 heart tired, calm. Grow up, mature, this society read. Tired and sad, squat down, to their a hug. Because the world no one can sympathize with you, have mercy on you. You cry, tears is your own。 life happy and worry, all is you of life attitude, optimistic, good luck。t 6, when we are in a positive frame of mind, you will find many good things。 I am not afraid of the truth to tell the best friend, I39。t want to face, don39。t always take everything back to things, and don39。 not disillusioned after the heart, such as ashes, but experience the storm after the enlightenment。 to discipline a ruler, often the control inspection, and consciously in the ideological red line to draw the row Ming Good accumulation is indeed the bottom line, so that the heart has fear, said to have quit, the line has ended. Attached: indifferent to heart, calmly to the table in our life, there are many unpredictable things will happen, some good, some bad things, we cannot control is powerless to stop, but with time, you will find in life sometimes turns out to be not good, some bad things finally turned out to be a good thing, but then we muddy however did not know, this is the life teach us things. 1, life can be plex, can also be simple. Want simple life of precipitation, to have enough time to reflect, to make Bee more perfect. Life is the most important thing is not to win, but the struggle。解：噴口的相對(duì)速度 牽引速度： 絕對(duì)速度切向分量： 所需轉(zhuǎn)動(dòng)力矩 （英文版 ） easily blame, to prevent the broken window effect. Supervise the leading cadres to play an exemplary role, take the lead in the strict implementation of the code and rule , lead to safeguard the solemnity and authority of the party discipline, ensure that the party discipline and the laws and regulations for implementation in place. Throughout the discipline in the daily supervision and management, strengthen supervision and inspection, from the thorough investigation of violations of discipline behavior. Strengthen to key areas, key departments and key projects as well as the masses reflect the concentration of the units and departments for supervision. strengthening supervision, discipline inspection and supervision of cadres to set an example for pliance with the code and rule is a man must be hexyl, blacksmith needs its own hardware. Discipline inspection organs as the executor of the party discipline, and supervisor of the defenders, for its supervision must be more strictly, discipline inspection and supervision of cadres to firmly establish the awareness of Party Constitution, sense of discipline and rules consciousness, politics loyalty, sense obey. Action speak Ji Ordinance to set an example of the regulations of the rule of law, strengthen supervision and accept the supervision of the firmness and consciousness, do ply with and . To firmly establish the discipline must first be disciplined, the supervisor will be subject to the supervision of concept, and consciously safeguard and implement party passes party, take the lead in practicing three strict real strict, so loyal, clean, play. To be good at learning, the Constitution and the code as morality, politics and brought to fruition。試求：（1）旋臂的旋轉(zhuǎn)角速度；（2）如果使已經(jīng)有角速度的旋臂停止，需要施加多大的外力矩。求噴水器的轉(zhuǎn)速n。噴嘴1和噴嘴2到轉(zhuǎn)動(dòng)中心的臂長分別為和。解：左 其中 右 即得 ，水從轉(zhuǎn)動(dòng)中心進(jìn)入，經(jīng)轉(zhuǎn)壁兩端的噴嘴噴出。求運(yùn)動(dòng)的葉片受到水射流的作用力和功率。解： 得：平板運(yùn)動(dòng)所需功率： ，截面積為A，以不變的流速v0，水平切向沖擊著以等速度v在水平方向作直線運(yùn)動(dòng)的葉片。（忽略流體撞擊損失和重力影響。（不計(jì)損失）解：（當(dāng)為絕對(duì)壓力時(shí)）由連續(xù)性方程 由動(dòng)量方程： 得： （當(dāng)為相對(duì)對(duì)壓力時(shí)）由連續(xù)性方程 由動(dòng)量方程： 得： ，一股射流以速度水平射到傾斜光滑平板上，體積流量為。解：取向右為正方向，因水流經(jīng)過葉片時(shí)截面積不變，所以流速大小不變F0=ρv0A0(v0v0)=2ρv(D02/2)即 解：由題意得，取1與2 過流斷面，列連續(xù)性方程得列能量方程，得 其中 設(shè)螺栓所需承受的力為F，列動(dòng)量方程，得 已知=300Pa, =300mm , =2m/s , =100mm,把它們代入以上各式，解得F= 水流經(jīng)由一份差噴嘴排入大氣中（pa=101kpa）。解：由Pa 得Hs= ，出口直徑，管端直徑，流量，噴嘴和管以法蘭盤連接，共用12個(gè)螺栓，不計(jì)水和噴嘴重量，求每個(gè)螺栓受力為多少?解：由連續(xù)性方程 得 由 把 代入 得 動(dòng)量方程 得 單個(gè)螺栓受力 ，導(dǎo)葉將入射水束作180176。假設(shè)裝在水泵與水管接頭上的真空計(jì)指示出現(xiàn)負(fù)壓值為39997Pa?？諝庾枇Σ挥?jì)，求噴嘴進(jìn)口的相對(duì)壓力和出口處的直徑。解：取斷面0和斷面1，有 斷面2和斷面1得 = m 救火水龍頭帶終端有收縮噴嘴。管道直徑D=50mm，管道上收縮出差壓計(jì)中h=,h=40kpa,d=25mm。解：由能量守恒定律 得連續(xù)性方程 = 所以 ，閘門關(guān)閉時(shí)的壓力表的讀數(shù)為49kPa，閘門打開后，有管進(jìn)口到閘門的水頭損失為1m，求管中的平均流速。求A、B、C、D各點(diǎn)的相對(duì)壓力和通過管道的流量。假設(shè)煤氣的密度為，管徑為50mm，壓力損失AB斷為，BC斷為，C點(diǎn)要求保持余壓為300Pa，求A點(diǎn)U型管中酒精液面高度差。當(dāng)（1）氣體為與大氣溫度相同的空氣時(shí)：（2）氣體密度為=，分別求管中流速、流量及管長一半處B點(diǎn)的壓力。取管軸線為基準(zhǔn)線，且hw01=0,則列出00，11兩個(gè)緩變流斷面之間的能量方程為：0+Pa/ρg+0=0=P1/ρg+v12/2g而P1=PahmmHg，所以v=qv=解：取1和2 兩個(gè)過流斷面，2為基準(zhǔn)面，由伯努利能量方程得 則 解得=取2和3兩個(gè)過流斷面，3為基準(zhǔn)面，由伯努利能量方程得 則解得=設(shè)收縮段的直徑應(yīng)不超過d，由連續(xù)性方程得， 則 = 氣體由靜壓箱經(jīng)過直徑為10cm，長度為100m的管流到大氣中，高差為40m。解： 又 則已知，代入上式得： 由連續(xù)性方程 又D=解得 d= ，軸流風(fēng)機(jī)的直徑為d=2m，水銀柱測壓計(jì)的讀數(shù)為△h=20mm，／m3 試求氣流的流速和流量。從噴嘴中排入大氣的水流速度，不計(jì)流失損失，計(jì)算11處所需要的相對(duì)壓力。解：（1）由（2） 即水流的方向?yàn)閺?到2，其過程中有能量的損失。解：(1)V(A1+ A2)= qv qv=3m/s（+）(2) qv =VA=Vd= 水流過一段轉(zhuǎn)彎變徑管，已知小管徑，截面壓力，大管直徑，壓力，流速。若三通管中各段水流的平均流速均為3m/s。解：因?yàn)関=qA/A所以v1=qA/A1=2700/(300x400x106)=22500m/h=V2=qA/A2=2700/(150x400x106)=45000m/h= 漸縮噴嘴進(jìn)口直徑為50mm，出口直徑為10mm。33 已知平面流動(dòng)的速度分布規(guī)律為解：流線微分方程：代入得： 截面為300mm400mm的矩形風(fēng)道，風(fēng)量為2700m3／h，求平均流速。 已知流場的速度分布為： （1）求點(diǎn)（3，1，2）的加速度。：U=(4x2+2y+xy)i+(3xy3+z)j(1) 求點(diǎn)（2,2,3）的加速度。(2) 是幾維流動(dòng)？(3) 是穩(wěn)定流動(dòng)還是非穩(wěn)定流動(dòng)？解：依題意可知，Vx=4x2+2y+xy ,Vy=3xy3+z ,Vz=0ax=+ vx+vy+vz=0+(4x2+2y+xy)(8x+y)+(3xy3+z)(2+x)=32x3+16xy+8x2y+4x2y+2y2+x y2+6x2 y3+2z+3 x2x y3+xz同理可求得，ay=12 x2+6y+3xy9x y2+3 y53 y2zaz=0代入數(shù)據(jù)得，ax= 436,ay=60, az=0a=436i+60j(2)z軸方向無分量，所以該速度為二維流動(dòng)(3)速度，加速度都與時(shí)間變化無關(guān)，所以是穩(wěn)定流動(dòng)。 （2）是幾維流動(dòng)？解：（1）由得： 把點(diǎn)（3,1,2）帶入得加速度a（