外文翻譯--流體力學(xué)和流體機(jī)械概述【中英文文獻(xiàn)譯文】

外文翻譯--流體力學(xué)和流體機(jī)械概述【中英文文獻(xiàn)譯文】,中英文文獻(xiàn)譯文,外文,翻譯,流體力學(xué),以及,流體,機(jī)械,概述,中英文,文獻(xiàn),譯文 The hydordynanmics and the fluid machineries The hydordynanmics is can be applied in in many ways, this makes the hydordynanmics become all engineering sums and should full one of the important courses of foundation in the science.The fluid run within piping, the water ?t says for the civil engineer that is very important to be like the research of the fluid machineries, such as water aspirator, compressor, heat exchanger, nozzle and the rocket engine...etc., make hydordynanmics say for the mechanical engineer also very important.The air current rounds a phenomenon of aerodynamics of substance is an interested in basic question of the aviation aerospace engineers that designs the airplane, guided missile and rockets the atmosphere and oceanses are all a fluid, so the research of the convection body is meteorology, hydrology and the foundation of the oceanographies.Today, many new theories put together the hydordynanmics and classic theory tie in modern engineering.For example study to call it as to give or get an electric shock the magnetohydrodynamics, MHD together the hydordynanmics and the electromagnetism, electromagnetics theory combinations.In newly) the capacity conversion apparatusof the type, the battery magnetohydrodynamics, MHD is necessary in phenomenon study star and ionosphere We can see, saying for the engineer of the modern and scientist that acquaint with the hydordynanmics is very necessary.Obviously, hydordynanmics and its applications are a course that has the extensive professional realms. In the solid rigid body mechanics, we usually ask thus a question:What is the tiny clique position function concerning time?Pass other ll questions of this condition, for example, what speed and accelerations are, can answer.If the position vector r represents the place of the tiny clique, so the r( t) is a count for much parameter. However.In the fluid we but the twin anti is a tiny clique, what we pay attention to is a continuous stream actually.We need not on the trail of each tiny clique or even a handful of several runnings of liquid are contrary, the question that to ask is:A little bit some place in the space, what speed, acceleration and the thermodynamic property function concerning times are that should order?Change along with the time, the fluid that should order is constantly the sum to flow through its new fluid occurrence to interchange the action, so we do not follow any running of clique with tiny fluid but the research space a little bit some circumstance of change that at any time ask, but ignore in the any and particular time by luck is what fluid in the way of this kind of description fluid call Euler method, with its opposite description method call the method of day of tractive lattice àê , the method of day of the lattice àê of tension is used for the description is in the rigid body mechanics a running of tiny clique. Spoke of a phrase before:Connect the stream from the fluid of angle see, what meaning does that phrase have?We suppose the space of the fluid tiny clique( or molecule), or say more by the square to is an equally free stroke very small.We say very small compare the hydordynanmics theory application in the physics size of the actual question with us but talk.In aerodynamics study, the aerofoil thickness than round the average and free stroke of the air current of the super - aerofoil to want big and many quantisty stages.So we suppose all processes of limit are meaningful, but the people is keeping any fluids of volume of the continuity circumstance F and canning be divided into very obvious and end this kind of division of smaller volume under very difficult progress go to, but we suppose this division and can carry on, this is very small because of the size of the tiny clique, seeing from the angle of tiny view, this hases no influence to our research. In can't press flow, the energy equation anti is necessary, because the density has already know.For describing the fluid run completely, need to solve the pressure and speeds only.At this time the temperature is a separation of, if request to solve the temperature then the demand uses the energy equation The fluid machinery mean those transport the fluid capacity or from sample the capacity in the fluid of equipments of machinery.The number first class fluid machinery knows together as the water aspirator, but the second fluid machinery be constitute by the turbine.Although also involved other machineries, the multiple point is the turbine machinery, namely those with shaft of running to deliver the water aspirator and the turbine of the capacity. Have three turbines of the type type in common usely, they respectively is:The Pelton water turbine sum two kinds of reaction turbine- Francises turbine sum propels the type turbine.The Pelton turbine is a kind of turbine of pulsation type, it includes the ring shape blade that a ring seeparate, the Pelton complete the operate towards seeparating the improvement of the blade to make water turbine can nicely, and therefore the water turbine also got the extensive application.The jet( or several jets of the large scale system) direction of the water with give the direction of settle the blade contrary, and tie the anti to bounce back to fly to again each side in the blade that seeparate, as a result pass impact load blade.When the turbine running, the blade and jets that each one follow become a straight line. The Francis turbine centre in typical model, the water current take to be pass by the leading blade of slice toward quantisty into the outside circumference, the turbine blade designs to make the water current follow the diameter thus to flow through the turbine blade, the fluid lost the angular momentum, so plused a turning moment for blade.Though the first Francis turbine is to leave the cenre type turbine, they are usually combination that leaves the cenre type and the shaft stream types currently, its blade usually screw the water current direction from diameter to for the shaft to. Second reaction turbine, be called to propel the type turbine, is the shaft stream type basically of.Be like the Francis turbine, the propulsion type turbine also reduced the angular momentum of the fluid, as a result also produced a turning moment in propeling the blade.Blade slopes of most moderns propulsion type turbine are all adjustable, in order to in within the scope of certain displacement higher effciency of sustaining.Such apparatus is called the Kaplan turbine. Almost all turbines are direct to connect with each other with generator set, so the turbine must keep the almost unchanged revolution speed, this is the synchronizing speed.This from adjust soon the machine sustaining of speed, from dynamo the number sum of the electrode produces the electric current of frequency to decide.For 60 electric currents of the Hertzs( the number of times of cycle of every second), the speed N( the revolving speed of every minute), from the formula N= the 7200/ np give settle, but the np is the electrode number of the dynamo, and must be the even integer. The pulsation type turbine and of the reaction turbines are most standard distinct is a reaction turbine to full to be surround by the liquid, but the pulsation type turbine then is not.Can see, the Pelton water turbine must from the pressure unchanged jet acquisition capacity, as a result the capacity is only can from the kinetuc energy of the fluid in acquisition. The water of the ex- bath or head of ?t be spread by a duct that is called to lead the service pipe pass toward turbine, but at this time the nozzle that then need to be a to design with meticulous care to raise the capacity that the jet velocity well makes and can acquire to maximize.Displacement from a hand type valve control, and a by - pass valve or the jet convertor assembly are in common use to protect this system, keeping the system amount of internal flow from nasty play to reduce.If the hand type valve must turn off quickly, an overflow water tank can also be the substitute to reduce the ripples of water pressure or the influence of the water hammers.Because the wake is impossible to restore again the residue capacity of the fluid, the water current goes in to turn on water ?t or the path of the wake surface the followings not to bring about any influence on the function of the Pelton water turbine.The Pelton water turbine usually is to set on-line in a horizontal axis, and the direct sum dynamo connect with each other, usually is two water turbine in balance set in the dynamo of both sides drive the same of shaft together. Although the turbine occasionally useds for some small scaled machineries of drive, they used for the quotient of the large and valuable equipments' use to generate electricity almost and all substantially up.The application is only the most standard type in the indrstry.Actually, these three turbines of the type type can immediately overlay all indrstries operation condition.On the other hand, the type of the pump is then a lot of, etc. from the small scaled water aspirator that every minute provides only several waters to the giant water aspirator anti that presses the prinipal far to draw to take the 300 cfs liquid every minute from several 100 foots, ignore to press for life with the water with it, still fuel pump in the autocar, lubricate the oil pump or cool off the oil pump, still used for the household appliance,such as washing machine, dishwasher and refrigerators,, in our daily life, we are few need not to pump, the type and model numbers that therefore pumps are a lot of.We pay attention to only among them the most important a kind of. Be like the turbine, most pumps are the turbines machinery, but have no the place of the likeness with the pulsation type turbine.According to the prinipal stream work direction, we will pump to is divided into three kinds of, they respectively is:The diameter mixs the water aspirator of stream type toward type( leave the cenre type), the shaft stream type( propel the type) sum.Pump is different from turbine, various applied sizes and type that pumps did not correspond with it of arrange or the typical model set the type.The population or low-pressure sides of the pump be called to draw water the port, but the outlet or the high pressure sides be called a water port.If request liquid from low in the place extract of the pump place, the pumps of then most types all in advance to fill up pump liquid. make the pump be able to start draw to take the liquid, sample the liquid thus and availably and continuously.This also requests to draw the perpendicular height difference of take the side enough small, the pressure of the pump neighborhood is no lower than the vapor to press, making the lifting liquid make possible.What further demand notice is, must insure the low pressure for pump to flow small will cause air pocket produce.Although the turbine useds for the water almost and all, the pump almost useds for the liquid of various type, even including the solid liquid mix.The pumping of the gas or use the blower, or use the compressor. Leave the cenre type, the shaft stream type sum mixs the stream type pump of basic operate priniple is contrary to the priniple of the reaction turbine. pump to is drive by motor or other machinerieses namely, and plus a torque on the fluid, be the fluid flow through increased the fluid of angular momentum, then the place that pump offsetted the angular momentum of the increase, making capacity increase. For a diameter of typical model to type or leave the cenre type pump, water current at shaft toward the place enter and because of propeller of action is compelled to follow the diameter to jilt, can have the pan shape tank or the cover, covering objects to use in the both sides of the oar flake to lift high-efficiency, or the oar flake is an open type, thus although lowered the effciency, make the propeller become the not easy bott.Have the quiet diffusion or the leading waves in spite of, pump to usually all have a spiral ?? .If all have the fluid into from two sides of the propeller, the pump becomes the double to draw the liquid propeller. Basic information Version order: 1 ISBN: 7302067201 Country do not: China is big six Publisher: University publisher of Chin Hua Simplify to pack: Paper back