Двигатели внутреннего сгорания. 2010. №2 PDF (Size:7770 МБ)

Рабочие процессы ДВСNumber of droplets, %Droplets diameter, μmFig. 1. Fuel oil atomization characteristicsIt is also described different factors and their influenceupon the dispersion and uniformity of the atomizationthere. But probably units on the vertical coordinateaxis on fig. 1 cannot be expressed in %. Andtherefore the diagrams can be referred to as just a preliminaryimage of atomization characteristics.In the monograph [2, p. 166-197] it is consideredproblems of coal-water slurries atomization quality.There are criterion relationships for a spray dropletsmean diameter by Sauter. But there are no curves of adensity of the droplets diameter distribution there.In the study guide [5, p. 192-197] attention ispaid to fuel oil atomization and it is shown on fig. 2,[5, p. 195, fig. 7.4] the fuel oil atomization characteristicfor a six-cylinder four-stroke supercharged dieselengine with 25 cm bore and 34 cm stroke.μmFig. 2. Fuel oil atomization characteristicOn the fig. 2: 1 – relative frequencies curve of thecharacteristics, 2 – relative summary curve. For thesummary curve: d k – diameters of droplets, n – totalnumber of droplets that have dimensions form minimumup to the given diameter, n c – the total number ofdroplets. For differential curve 1: d k – given value ofdroplets sizes, d(n/n c ) – the increase of the dropletsnumber, d(d k ) – the increase of the diameter.However like in the work [1, p. 101, fig. 39] thedensity of the distribution measured in % which apparentlyis not correct. Moreover in the related text blockit is mixed numbers that denote differential and cumulativecurves.In the newest publication [6, p. 174] denoted theutmost importance of the size of the fuel droplets forthe combustion process quality. Although there is noany curves of the size distribution.An attempt to analyze some parametric researcheson reologic properties of coal-water slurriesfor their use in ships’ internal combustion engines wasmade in the paper [7]. It is quite natural to continueanalytical researches in the field of fuel supply flow,injection, and spraying.Analytical researches was made in the monographs[3, 4], where it was given a theoretical backgroundfor solving problems of a technical state on thebasis of subjective analysis and problem-resource approach.As it is seen from above mentioned speculationsthere is a necessity to remind principles of statisticalestimations and using them to get the low of distribution.Problem settingThe intention of the given paper is to research theadequacy between experimental and theoretical distributionsfor fuel oil atomization characteristics. Also itis to plot diagrams of distribution curves and test thehypothesis of a logarithm normal distribution.Main materialIt is necessary to determine droplets diameter of aspray before plotting atomization characteristics. It canbe used one of the simplest and most commonly usedway of putting a smoked plate into the spray. Then thedroplets dimensions have to be measured with the helpof a microscope [1, p. 101; bilo, p. 174].After this procedure we get so-called “simple statisticalsample” or “simple statistical series”. The simplestatistical sample is a primary form of a statisticalmaterial registration and can be proceeded in differentways. One of the ways of such a treatment is plotting astatistical function of a distribution of the random variable[8, p. 134].ДВИГАТЕЛИ ВНУТРЕННЕГО СГОРАНИЯ 2'2010 35