The phenomenon of the cavitation occurs by an abrupt fall of the pressure of a fluid below the vapour pressure, this must to abrupt changes in the speed of the flow or by an effect of it drained partisan given generally by great columns of fluid as it is the case of the pumps. In practical terms this fall of pressure, brings about the formation of steam bubbles, which travel by the fluid until in another place, the pressure is restituted bringing about an abrupt condensation of gases, generating an implosion, this determined fort impact, in the contiguous surfaces since the denominated effect of the shaped charge is generated or Monroe, in which they themselves converge all the waves to a same place confining itself, this generates punctures very important that they end up destroying the metal. It is also known that these gas bubbles sometimes are not such, as all we know the fluids are non-compressible, but due to special conditions of speed variation, the fluid withdraws momentarily, being created a hole, that does not have gas it has or it in very little measurement, immediately later when the speed is regularized, the molecules of the fluid hurry abruptly towards the orifico which I am generated, causing a fort hits in the convergence point, the same that goes, towards the place where there were no molecules hurrying, that are the wall of the next surface. As it is known the elements, that undergo the greater deterioration by this type of phenomenon are the helices, the pumps, fuel pipes, turbines of hydroelectric generation, rudders of boats, etc. Although the cavitation is a phenomenon normally identified like negative and necessary to avoid, by his effects it has two useful applications essentially, the cleaning, by means of cavitation and ultrasound and the denominated supercavitation, which allows the movement of a body submerged in a fluid, at speeds the 500 superiors to Km/h even near the sonic speed, at the moment is investigated widely with military objectives. It is not very easy to avoid the cavitation, since the liquid means cannot be controlled in many case, for these case which becomes is to modify geometries of the elements and/or to realise a careful sizing of the involved equipment. When the fluid can be controlled, as it is the case of fuel pipes or lines of water cooling, can be made use to some alternatives, like slow down of flow, maintaining cleanest the fluid possible, to diminish the temperature of the same, or to place dampers that the fluctuations of speed absorb The cavitation usually is detected by the noise that causes which is similar pebble snore even moving this also generates vibration that is easily detectable especially because they are possible to be appreciated in graphic the denominated humps of camel, unequivocal sign of the phenomenon cavitatorio. The cavitation although is light, brings about clean wearing down since the surface of the metal, of the oxide, which is a layer, protector leaving to shortage the metal, at that moment is created a galvanic battery, that increases the erosion of the surface, since the metal this subject to the action of the cavitation and the one of the corrosion destroying itself very quickly Original author and source of the article.
There are many types of grass around the world, many of whom are not artificially grown or are not cultivated by man. Among those many that exist, the man only cultivated a small amount of them. Among all types of grass that man can cultivate are types of turf for all sorts of uses: thus there is grass specializing in cattle for livestock food, there are types of grass used for gardens, there are lawn special types for sports and recreation, among other many uses that can have different types of grass. Among these crop types by man and have specific uses is the common creeping. Indeed, the common creeping is a type of grass very known because it has its own uses and its own characteristics. Let’s see some of these traits that enjoys common creeping.
The common creeping has several names. Thus, it can be found under the scientific name of Agrostis Tenuis. You can also be found under common names such as agrostis, creeping Dim, smoky Hay, among other names with which it is commonly known in various parts of the world. Anyway, one of the best-known names if it is of common creeping. The common creeping is called thus possibly because among all types of agrostides, it is that can more easily be to sow, is you can get cheaper and which grows possibly easier, since you don’t need both as other seeds of creeping in order to grow on Earth. The common creeping is widely used on golf courses.
Although ideal lawn for use on golf courses has been the turf of cumberland, since the latter is very expensive and not always can be kept, many of the golf courses they opt to use the common creeping to its operation, to be used only or that they choose to use common creeping by mixing it with other types of lawn as the same lawn of cumberland. last sta combination has given an excellent result in the fields of golf who choose to use it. The common creeping is also widely used in gardens that have a significance and special care. Since one of the qualities of the common creeping consists that you can mix with many types of grass without difficulty, this is combined with finer grass types for different gardens in an aesthetically pleasing manner. With the help of the common creeping combined with these types of grass more expensive and more difficult to maintain, gardens save many expenses in maintenance and investment still enjoying a beautiful lawn to show to people who witness these gardens. While the common creeping is a type of grass rather cheap for planting, should take into account that this demands a good maintenance. The common creeping does not tolerate well two things that make it to be somewhat tricky: first not well resists the constant stomping of persons. In second common creeping is not good to withstand the heat. his is a type of grass that will easily suffer when exposed to the heat of the summer, especially when the heat that there is dry heat. In these cases be must moisturize constantly creeping common lawn to keep it in good condition.