{"id":3736,"date":"2016-06-06T10:27:09","date_gmt":"2016-06-06T07:27:09","guid":{"rendered":"http:\/\/www.romconvert.ro\/new\/?post_type=portfolio&#038;p=3736"},"modified":"2016-06-13T18:20:33","modified_gmt":"2016-06-13T15:20:33","slug":"simularea-proceselor-hidrodinamice-din-echipamentul-de-injectie-al-motoarelor-diesel-conferinta-nationala-de-termotehnica","status":"publish","type":"portfolio","link":"https:\/\/www.romconvert.ro\/new\/index.php\/portfolio-item\/simularea-proceselor-hidrodinamice-din-echipamentul-de-injectie-al-motoarelor-diesel-conferinta-nationala-de-termotehnica\/","title":{"rendered":"Simularea proceselor hidrodinamice din echipamentul de injec\u0163ie al motoarelor diesel"},"content":{"rendered":"\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-av_section-541a21edc89c4228c055bf0ea5d58e9e\">\n.avia-section.av-av_section-541a21edc89c4228c055bf0ea5d58e9e{\nbackground-color:#303030;\nbackground-image:unset;\n}\n<\/style>\n<div id='av_section_1'  class='avia-section av-av_section-541a21edc89c4228c055bf0ea5d58e9e main_color avia-section-default avia-no-shadow  avia-builder-el-0  el_before_av_section  avia-builder-el-first  avia-bg-style-scroll container_wrap sidebar_right'  ><div class='container av-section-cont-open' ><main  role=\"main\" itemprop=\"mainContentOfPage\"  class='template-page content  av-content-small alpha units'><div class='post-entry post-entry-type-page post-entry-3736'><div class='entry-content-wrapper clearfix'>\n<section  class='av_textblock_section av-av_textblock-0366cc7376be6c9e82a3e9cc8987b64f '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/CreativeWork\" ><div class='avia_textblock'  itemprop=\"text\" ><h3 style=\"text-align: center;\"><span style=\"color: #ffffff;\">SIMULAREA PROCESELOR HIDRODINAMICE DIN ECHIPAMENTUL DE INJEC\u0162IE AL MOTOARELOR DIESEL, CONFERIN\u0162A NA\u0162IONAL\u0102 DE TERMOTEHNIC\u0102<\/span><\/h3>\n<\/div><\/section>\n\n<\/div><\/div><\/main><!-- close content main element --><\/div><\/div><div id='av_section_2'  class='avia-section av-av_section-915b33fd1d6006bfc684ade488387eaf main_color avia-section-default avia-no-border-styling  avia-builder-el-2  el_after_av_section  el_before_av_section  avia-bg-style-scroll container_wrap sidebar_right'  ><div class='container av-section-cont-open' ><div class='template-page content  av-content-small alpha units'><div class='post-entry post-entry-type-page post-entry-3736'><div class='entry-content-wrapper clearfix'>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-av_heading-cb4b7c5f3927f27712bb34aae8b39a9e\">\n#top .av-special-heading.av-av_heading-cb4b7c5f3927f27712bb34aae8b39a9e{\npadding-bottom:20px;\ncolor:#020202;\n}\nbody .av-special-heading.av-av_heading-cb4b7c5f3927f27712bb34aae8b39a9e .av-special-heading-tag .heading-char{\nfont-size:25px;\n}\n.av-special-heading.av-av_heading-cb4b7c5f3927f27712bb34aae8b39a9e .special-heading-inner-border{\nborder-color:#020202;\n}\n.av-special-heading.av-av_heading-cb4b7c5f3927f27712bb34aae8b39a9e .av-subheading{\nfont-size:16px;\n}\n<\/style>\n<div  class='av-special-heading av-av_heading-cb4b7c5f3927f27712bb34aae8b39a9e av-special-heading-h2 custom-color-heading blockquote modern-quote modern-centered  avia-builder-el-3  el_before_av_one_fourth  avia-builder-el-first '><h2 class='av-special-heading-tag '  itemprop=\"headline\"  >1. Introducere<\/h2><div class='av_custom_color av-subheading av-subheading_below'><p>Fenomenele hidrodinamice din echipamentul de injec\u0163ie al motoarelor diesel pot fi reprezentate printr-un model multidimensional de simulare numeric\u0103. Acesta permite definirea domeniului de integrare a ecua\u0163iilor \u00een conformitate cu geometria real\u0103 a spa\u0163iilor prin care curge combustibilul. Procedeul este foarte util \u00een procesul de proiectare a echipamentelor noi, sau de modernizare a celor existente.<\/p>\n<\/div><div class=\"special-heading-border\"><div class=\"special-heading-inner-border\"><\/div><\/div><\/div>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-av_one_fourth-9497bbf8bff73ea4c6992cc17fa9ec36\">\n.flex_column.av-av_one_fourth-9497bbf8bff73ea4c6992cc17fa9ec36{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\n}\n<\/style>\n<div  class='flex_column av-av_one_fourth-9497bbf8bff73ea4c6992cc17fa9ec36 av_one_fourth  avia-builder-el-4  el_after_av_heading  el_before_av_one_half  first flex_column_div av-zero-column-padding  '     ><\/div>\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-av_one_half-9c1d454dc06f7247226bc4e8f931daae\">\n.flex_column.av-av_one_half-9c1d454dc06f7247226bc4e8f931daae{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\n}\n<\/style>\n<div  class='flex_column av-av_one_half-9c1d454dc06f7247226bc4e8f931daae av_one_half  avia-builder-el-5  el_after_av_one_fourth  el_before_av_one_fourth  flex_column_div av-zero-column-padding  '     ><div  class='avia-button-wrap av-av_button-b18f3ed5362930dda4fa504c7208e57d-wrap avia-button-center  avia-builder-el-6  avia-builder-el-no-sibling '>\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-av_button-b18f3ed5362930dda4fa504c7208e57d\">\n#top #wrap_all .avia-button.av-av_button-b18f3ed5362930dda4fa504c7208e57d{\nbackground-color:#ed3636;\nborder-color:#ed3636;\ncolor:#ffffff;\ntransition:all 0.4s ease-in-out;\n}\n#top #wrap_all .avia-button.av-av_button-b18f3ed5362930dda4fa504c7208e57d .avia-svg-icon svg:first-child{\nfill:#ffffff;\nstroke:#ffffff;\n}\n<\/style>\n<a href='http:\/\/www.romconvert.ro\/new\/wp-content\/uploads\/2016\/06\/Simularea-proceselor-hidrodinamice-din-echipamentul-de-injec\u0163ie-al-motoarelor-diesel.pdf'  class='avia-button av-av_button-b18f3ed5362930dda4fa504c7208e57d av-link-btn avia-icon_select-yes-left-icon avia-size-large avia-position-center av-icon-on-hover'  target=\"_blank\"  rel=\"noopener noreferrer\"  aria-label=\"DESC\u0102RCARE ARTICOL\"><span class='avia_button_icon avia_button_icon_left avia-iconfont avia-font-entypo-fontello' data-av_icon='\ue812' data-av_iconfont='entypo-fontello' ><\/span><span class='avia_iconbox_title' >DESC\u0102RCARE ARTICOL<\/span><\/a><\/div><\/div>\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-av_one_fourth-9c1d454dc06f7247226bc4e8f931daae\">\n.flex_column.av-av_one_fourth-9c1d454dc06f7247226bc4e8f931daae{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\n}\n<\/style>\n<div  class='flex_column av-av_one_fourth-9c1d454dc06f7247226bc4e8f931daae av_one_fourth  avia-builder-el-7  el_after_av_one_half  avia-builder-el-last  flex_column_div av-zero-column-padding  '     ><\/div><\/div><\/div><\/div><!-- close content main div --><\/div><\/div><div id='av_section_3'  class='avia-section av-av_section-d18d8c2c81d10022ebd21ffa95322c35 main_color avia-section-default avia-no-shadow  avia-builder-el-8  el_after_av_section  el_before_av_one_full  avia-bg-style-scroll container_wrap sidebar_right'  ><div class='container av-section-cont-open' ><div class='template-page content  av-content-small alpha units'><div class='post-entry post-entry-type-page post-entry-3736'><div class='entry-content-wrapper clearfix'>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-av_one_full-9497bbf8bff73ea4c6992cc17fa9ec36\">\n.flex_column.av-av_one_full-9497bbf8bff73ea4c6992cc17fa9ec36{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\n}\n<\/style>\n<div  class='flex_column av-av_one_full-9497bbf8bff73ea4c6992cc17fa9ec36 av_one_full  avia-builder-el-9  el_before_av_one_full  avia-builder-el-first  first flex_column_div av-zero-column-padding  '     ><\/div>\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-av_one_full-9497bbf8bff73ea4c6992cc17fa9ec36\">\n.flex_column.av-av_one_full-9497bbf8bff73ea4c6992cc17fa9ec36{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\n}\n<\/style>\n<div  class='flex_column av-av_one_full-9497bbf8bff73ea4c6992cc17fa9ec36 av_one_full  avia-builder-el-11  el_after_av_one_full  avia-builder-el-last  first flex_column_div av-zero-column-padding  column-top-margin'     ><style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-av_textblock-3326d3317592321e340dbe8477480288\">\n#top .av_textblock_section.av-av_textblock-3326d3317592321e340dbe8477480288 .avia_textblock{\nfont-size:15px;\n}\n<\/style>\n<section  class='av_textblock_section av-av_textblock-3326d3317592321e340dbe8477480288 '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/CreativeWork\" ><div class='avia_textblock'  itemprop=\"text\" ><div class=\"as-text\">\n<h2 class=\"title\">2. Descrierea modelului<\/h2>\n<div class=\"title-detail\"><\/div>\n<p>Modelul matematic de simulare numeric\u0103 a stat la baza elabor\u0103rii unor programe de calcul \u015fi analiz\u0103 \u00een limbajul de nivel \u00eenalt Pascal, propriu mediului de dezvoltare BORLAND DELPHI.<\/p>\n<div class=\"as-sub-subtitle\">2.1. Ecua\u0163iile modelului<\/div>\n<p>Pentru modelarea curgerii combustibilului s-au utilizat ecua\u0163iile Navier-Stokes pentru cazul curgerii plane nesta\u0163ionare, turbulente, compresibile. Se face men\u0163iunea c\u0103 ecua\u0163iile Navier-Stokes completate cu termenii turbulen\u0163i formeaz\u0103 ecua\u0163iile lui Reynolds.<\/p>\n<p>Pentru cele dou\u0103 componente ale vitezei , conform [1], acestea sunt:<\/p>\n<div class=\"math-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-15.gif\" \/><\/div>\n<div class=\"math-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-16.gif\" \/><\/div>\n<p>Ecua\u0163ia continuit\u0103\u0163ii este dat\u0103 de rela\u0163ia:<\/p>\n<div class=\"math-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-17.gif\" \/><\/div>\n<p>Ecua\u0163ia compresibilit\u0103\u0163ii este:<\/p>\n<div class=\"math-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-18.gif\" \/><\/div>\n<p>Evaluarea termenilor turbulen\u0163i se face, conform [2], astfel:<\/p>\n<div class=\"math-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-19.gif\" \/><\/div>\n<p>Primul coeficient al ultimei egalit\u0103\u0163i din rela\u0163ia (6) reprezint\u0103 o facilitate matematic\u0103, el fiind introdus pentru a permite evaluarea termenilor, pe direc\u0163ia perpendicular\u0103 fa\u0163\u0103 de direc\u0163ia principal\u0103 de curgere, cu aceea\u015fi formul\u0103. Dac\u0103 turbulen\u0163a este izotrop\u0103, atunci coeficientul ia valoarea 1.<\/p>\n<p>La ecua\u0163iile de mai sus se adaug\u0103 ecua\u0163iile de echilibru dinamic ale supapei de refulare \u015fi ale acului injectorului.<\/p>\n<div class=\"as-sub-subtitle\">2.2. Problema cavita\u0163iei<\/div>\n<p>\u00cen masa combustibilului vehiculat prin echipamentul de injec\u0163ie apar pungi de vapori. Combustibilul se vaporizeaz\u0103 instantaneu, afect\u00e2nd dinamica curgerii atunci c\u00e2nd gradien\u0163ii de vitez\u0103 \u015fi de presiune sunt mari. Fenomenul se desf\u0103\u015foar\u0103 intens \u015fi afecteaz\u0103 suprafe\u0163ele pe l\u00e2ng\u0103 care se scurge motorina.<\/p>\n<div class=\"box-content\">\n<div class=\"as-image\"><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-1.gif\" \/><\/div>\n<div class=\"as-text\">\n<p>Se poate considera c\u0103 pe un interval de timp dt vaporii care apar sunt \u00een echilibru termodinamic cu lichidul din care provin.<\/p>\n<p>Motorina nefiind o substan\u0163\u0103 pur\u0103, curba de vaporizare nu este izobar-izoterm\u0103, ci se determin\u0103 experimental. Din figura 1 se observ\u0103 c\u0103 la presiuni mai mici de 130 Pa, temperatura de \u00eenceput de vaporizare scade sub 75 \u00b0C.<\/p>\n<p>Pentru modelul propus s-a luat \u00een calcul o temperatur\u0103 constant\u0103, de 75 \u00b0C, pe toat\u0103 durata desf\u0103\u015fur\u0103rii procesului de injec\u0163ie. Acestei temperaturi \u00eei corespunde o limit\u0103 de 133,4 Pa pentru presiune, ceea ce \u00eenseamn\u0103 c\u0103, ori de c\u00e2te ori presiunea local\u0103 devine mai mic\u0103 dec\u00e2t aceast\u0103 valoare, apar vapori de carburant.<\/p>\n<\/div>\n<\/div>\n<p>Cantitatea de vapori ap\u0103rut\u0103 local poate fi calculat\u0103, conform [4], cu rela\u0163ia:<\/p>\n<div class=\"math-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-20.gif\" \/><\/div>\n<p>unde:<\/p>\n<ul>\n<li>e &#8211; titlul de vapori;<\/li>\n<li>T &#8211; temperatura motorinei;<\/li>\n<li>T50VE &#8211; temperatura la 50% distilat pe curba VE (vaporizare \u00een echilibru);<\/li>\n<li>m &#8211; panta curbei VE la presiunea atmosferic\u0103 normal\u0103, calculat\u0103 cu formula:\n<div class=\"math-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-21.gif\" \/><\/div>\n<\/li>\n<\/ul>\n<p>Apari\u0163ia vaporilor \u00een masa de combustibil influen\u0163eaz\u0103 compresibilitatea acestuia.<\/p>\n<p>Compresibilitatea local\u0103 a fost definit\u0103 ca medie ponderat\u0103 \u00eentre compresibilitatea lichidului \u015fi compresibilitatea vaporilor, conform formulei:<\/p>\n<div class=\"math-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-22.gif\" \/><\/div>\n<p>unde:<\/p>\n<ul>\n<li>\u00df lichid (p) &#8211; compresibilitatea motorinei, faza lichid\u0103;<\/li>\n<li>\u00df vapori &#8211; compresibilitatea vaporilor de motorin\u0103, considera\u0163i gaz perfect.<\/li>\n<\/ul>\n<div class=\"as-sub-subtitle\">2.3. Integrabilitatea sistemului de ecua\u0163ii<\/div>\n<p>Se consider\u0103 sistemul neliniar de ecua\u0163ii scris sub forma restr\u00e2ns\u0103:<\/p>\n<div class=\"math-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-23.gif\" \/><\/div>\n<p>Dac\u0103 func\u0163iile notate cu indici de la 1 la 4 sunt definite \u015fi continue \u00een domeniul D al unui spa\u0163iu real cvadridimensional E4, atunci valorile acestor func\u0163ii, pentru vectorul (u,v,p,q) apar\u0163in\u00e2nd lui D, constituie un subdomeniu D&#8217; din E4. Sistemul de ecua\u0163ii (11) stabile\u015fte o aplica\u0163ie a domeniului D pe domeniul D&#8217;.<\/p>\n<p>Folosind nota\u0163iile vectoriale:<\/p>\n<div class=\"math-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-24.gif\" \/><\/div>\n<p>se poate scrie sistemul sub forma urm\u0103toare:<\/p>\n<div class=\"math-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-25.gif\" \/><\/div>\n<p>Se introduce \u00een spa\u0163iul E4 o norm\u0103 canonic\u0103 ||x|| definit\u0103 astfel: ||x|| = max|xi|. Aplica\u0163ia (13) se nume\u015fte contractant\u0103 \u00een domeniul D dac\u0103 exist\u0103 un num\u0103r q &lt; 1 astfel \u00eenc\u00e2t pentru dou\u0103 puncte oarecare x1 negat, x2 negat apar\u0163in\u00e2nd lui D, transform\u0103rile punctelor satisfac condi\u0163ia<\/p>\n<div class=\"math-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-26.gif\" \/><\/div>\n<p>Fie x* negat solu\u0163ia acestui sistem. Dac\u0103 ea exist\u0103, atunci este un punct fix al transform\u0103rii (13). Pentru a g\u0103si aceast\u0103 solu\u0163ie se poate construi urm\u0103torul proces iterativ:<\/p>\n<div class=\"math-image\"><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-27.gif\" \/><\/div>\n<p>Dac\u0103 aplica\u0163ia este contractant\u0103, procesul iterativ converge c\u0103tre punctul fix x*. Aceast\u0103 solu\u0163ie se atinge la limit\u0103, adic\u0103 dup\u0103 o infinitate de itera\u0163ii. \u00cen practic\u0103, calculul se opre\u015fte dup\u0103 un num\u0103r limitat de itera\u0163ii, atunci c\u00e2nd eroarea dintre dou\u0103 aproximatii succesive a sc\u0103zut sub o anumit\u0103 valoare impus\u0103.<\/p>\n<p>Datorit\u0103 complexit\u0103\u0163ii sistemului sunt dificil de utilizat diverse teoreme pentru a verifica dac\u0103 aplica\u0163ia asociat\u0103 acestuia este contractant\u0103 \u00een D sau nu. Trebuie avut \u00een vedere faptul c\u0103 sistemul scris pentru toate punctele domeniului de defini\u0163ie con\u0163ine circa 14.000 de ecua\u0163ii.<\/p>\n<p>Exist\u0103, totu\u015fi, posibilitatea verific\u0103rii pe parcursul desf\u0103\u015fur\u0103rii calculelor a afirma\u0163iei reciproce: dac\u0103 solu\u0163ia este convergent\u0103, aplica\u0163ia este contractant\u0103.<\/p>\n<p>Caracteristica re\u0163elei este definit\u0103 ca fiind raportul dintre pasul temporal \u015fi pasul spa\u0163ial, sau p\u0103tratul acestuia func\u0163ie de gradul ecua\u0163iei diferen\u0163iale cu derivate par\u0163iale din care a provenit rela\u0163ia.<\/p>\n<p>Deoarece \u00een ecua\u0163iile sistemului apar \u015fi derivate de ordinul \u00eent\u00e2i \u015fi derivate de ordinul doi, caracteristica re\u0163elei poate fi definit\u0103 astfel:<\/p>\n<div class=\"math-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/formule\/8-28.gif\" \/><\/div>\n<p>Pentru sistemul de ecua\u0163ii corespunz\u0103tor modelului, \u015fi pentru domeniile definite anterior, s-a reu\u015fit g\u0103sirea unei valori pentru caracteristica re\u0163elei astfel \u00eenc\u00e2t s\u0103 se ob\u0163in\u0103 solu\u0163ii cu eroarea de 1,05E &#8211; 0,5, impus\u0103 \u00een 9 \u00f7 11 itera\u0163ii.<\/p>\n<div class=\"box-content\">\n<div class=\"as-image\"><img decoding=\"async\" class=\"as-image\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-2.gif\" \/><\/div>\n<div class=\"as-text\">\n<p>Erorile (figura 2) s-au determinat pe fiecare dintre cele dou\u0103 componente, u \u015fi v, pentru presiunea p \u015fi densitatea q. Calculele au ar\u0103tat c\u0103 erorile pentru fiecare component\u0103 \u00een parte &#8211; u \u015fi v &#8211; sunt egale ca valoare. Din acest motiv s-a reprezentat numai o singur\u0103 curb\u0103 pentru ambele componente. Se observ\u0103 o descre\u015ftere uniform\u0103 a valorii erorii ob\u0163inute pentru dou\u0103 itera\u0163ii succesive, \u00een func\u0163ie de num\u0103rul de itera\u0163ii. Se pot ob\u0163ine astfel erori foarte mici \u015fi &#8211; \u00een consecin\u0163\u0103 &#8211; precizii suficient de ridicate pentru solu\u0163ie.<\/p>\n<\/div>\n<\/div>\n<h2 class=\"title\">3. Rezultate ob\u0163inute cu modelul propus<\/h2>\n<div class=\"title-detail\"><\/div>\n<p>Modelul matematic de simulare numeric\u0103 a stat la baza elabor\u0103rii unor programe de calcul \u015fi analiz\u0103 \u00een limbajul de nivel \u00eenalt Pascal, propriu mediului de dezvoltare DELPHI. Cu acestea s-au f\u0103cut simul\u0103ri pentru procesul de injec\u0163ie \u00een dou\u0103 cazuri: utilizarea \u00een instala\u0163ie a unei pompe de injec\u0163ie cu piston sertar \u015fi utilizarea unei pompe de injec\u0163ie cu distribuitor rotativ, de tip DPA. Pentru fiecare simulare \u00een parte s-au ob\u0163inut aproximativ 80 de fi\u015fiere, cu c\u00e2mpurile de presiune \u015fi viteze \u00een 14.000 de puncte ale domeniului considerat.<\/p>\n<p>Fine\u0163ea discretiz\u0103rii modelului a permis ob\u0163inerea profilului vitezei la jum\u0103tatea conductei (figura 3).<\/p>\n<div class=\"as-images row\">\n<div class=\"as-box col-lg-6 col-md-6 col-sm-6 col-xs-12\">\n<p><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-3.gif\" \/><\/p>\n<p>\u00cen figura 4 este de remarcat forma profilului vitezei la intrarea \u00een conduct\u0103. Acest profil cu trei v\u00e2rfuri se datoreaz\u0103 componentelor tangen\u0163iale din aceast\u0103 zon\u0103, componente generate de modificarea sec\u0163iunii \u015fi de forma supapei.<\/p>\n<\/div>\n<div class=\"as-box col-lg-6 col-md-6 col-sm-6 col-xs-12\">\n<p><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-4.gif\" \/><\/p>\n<p>Figura 5 prezint\u0103 c\u00e2mpul de viteze \u00een pomp\u0103, la 0,66 ms (4 grd. RAP), |Vmax| = 6,37 m\/s.<\/p>\n<\/div>\n<\/div>\n<div class=\"as-images row\">\n<div class=\"as-box col-lg-4 col-md-4 col-sm-4 col-xs-12\">\n<p><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-5.gif\" \/><\/p>\n<p>Figura 6 prezint\u0103 c\u00e2mpul de viteze \u00een pomp\u0103, la 1,66 ms (10 grd. RAP), |Vmax| = 6,23 m\/s.<\/p>\n<\/div>\n<div class=\"as-box col-lg-4 col-md-4 col-sm-4 col-xs-12\">\n<p><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-6.gif\" \/><\/p>\n<p>Figura 7 prezint\u0103 c\u00e2mpul de viteze \u00een jurul supapei, la 0,16 ms (1 grd. RAP), |Vmax| = 3,92 m\/s.<\/p>\n<\/div>\n<div class=\"as-box col-lg-4 col-md-4 col-sm-4 col-xs-12\">\n<p><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-7.gif\" \/><\/p>\n<p>Figura 8 prezint\u0103 c\u00e2mpul de viteze \u00een jurul supapei, la 0,66 ms (4 grd. RAP), |Vmax| = 4,83 m\/s.<\/p>\n<\/div>\n<\/div>\n<div class=\"as-images row\">\n<div class=\"as-box col-lg-4 col-md-4 col-sm-4 col-xs-12\">\n<p><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-8.gif\" \/><\/p>\n<p>Figura 9 prezint\u0103 c\u00e2mpul de viteze \u00een jurul supapei, la 1 ms (6 grd. RAP), |Vmax| = 6,78 m\/s. Supapa s-a oprit pe limitator.<\/p>\n<\/div>\n<div class=\"as-box col-lg-4 col-md-4 col-sm-4 col-xs-12\">\n<p><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-9.gif\" \/><\/p>\n<p>Figura 10 prezint\u0103 un detaliu al c\u00e2mpului de viteze \u00een pompa rotativ\u0103, la 0,1 ms, |Vmax| = 5,8 m\/s.<\/p>\n<\/div>\n<div class=\"as-box col-lg-4 col-md-4 col-sm-4 col-xs-12\">\n<p><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-10.gif\" \/><\/p>\n<p>Figura 11 prezint\u0103 un detaliu al c\u00e2mpului de viteze \u00een pompa rotativ\u0103, la 0,7 ms, |Vmax| =17,53 m\/s.<\/p>\n<\/div>\n<\/div>\n<div class=\"as-images row\">\n<div class=\"as-box col-lg-4 col-md-4 col-sm-4 col-xs-12\">\n<p><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-11.gif\" \/><\/p>\n<p>Figura 12 prezint\u0103 un detaliu al c\u00e2mpului de viteze \u00een pompa rotativ\u0103, la 0,1 ms, |Vmax| = 6,18 m\/s.<\/p>\n<\/div>\n<div class=\"as-box col-lg-4 col-md-4 col-sm-4 col-xs-12\">\n<p><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-12.gif\" \/><\/p>\n<p>C\u00e2mpul de presiuni pentru deschiderea supapei de refulare din pompa de injec\u0163ie este prezentat \u00een figura 13.\u00a0Zona goal\u0103 din suprafa\u0163a graficului reprezint\u0103 pozi\u0163ia momentan\u0103 a supapei de refulare.<\/p>\n<\/div>\n<\/div>\n<div class=\"as-images row\">\n<div class=\"as-box col-lg-6 col-md-6 col-sm-6 col-xs-12\">\n<p><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-13.gif\" \/><\/p>\n<p>C\u00e2mpul de presiuni \u00een pompa de injec\u0163ie pentru sf\u00e2r\u015fitul injec\u0163iei este prezentat \u00een figura 14.\u00a0Canalul de alimentare cu combustibil a fost deschis de pistonul sertar.<\/p>\n<\/div>\n<div class=\"as-box col-lg-6 col-md-6 col-sm-6 col-xs-12\">\n<p><img decoding=\"async\" src=\"http:\/\/romconvert.azurewebsites.net\/images\/as8\/8-14.gif\" \/><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div><\/section><\/div>\n<\/div><\/div><\/div><!-- close content main div --><\/div><\/div><div id='after_section_3'  class='main_color av_default_container_wrap container_wrap sidebar_right'  ><div class='container av-section-cont-open' ><div class='template-page content  av-content-small alpha units'><div class='post-entry post-entry-type-page post-entry-3736'><div class='entry-content-wrapper clearfix'><\/p>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-av_one_full-9497bbf8bff73ea4c6992cc17fa9ec36\">\n.flex_column.av-av_one_full-9497bbf8bff73ea4c6992cc17fa9ec36{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\n}\n<\/style>\n<div  class='flex_column av-av_one_full-9497bbf8bff73ea4c6992cc17fa9ec36 av_one_full  avia-builder-el-13  el_after_av_section  avia-builder-el-no-sibling  first flex_column_div av-zero-column-padding  '     ><style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-av_heading-21ddf0476f24f667d18978c5c04c854f\">\n#top .av-special-heading.av-av_heading-21ddf0476f24f667d18978c5c04c854f{\npadding-bottom:10px;\n}\nbody .av-special-heading.av-av_heading-21ddf0476f24f667d18978c5c04c854f .av-special-heading-tag .heading-char{\nfont-size:25px;\n}\n.av-special-heading.av-av_heading-21ddf0476f24f667d18978c5c04c854f .av-subheading{\nfont-size:15px;\n}\n<\/style>\n<div  class='av-special-heading av-av_heading-21ddf0476f24f667d18978c5c04c854f av-special-heading-h2 blockquote modern-quote  avia-builder-el-14  avia-builder-el-no-sibling '><h2 class='av-special-heading-tag '  itemprop=\"headline\"  >4. Concluzii<\/h2><div class='av-subheading av-subheading_below'><p>Simularea numeric\u0103 a proceselor hidrodinamice din echipamentul de injec\u0163ie al motoarelor diesel cu ajutorul modelului propus, eviden\u0163iaz\u0103 anumite aspecte specifice legate de curgerea combustibilului la presiuni mari. Modelul permite analiza influen\u0163elor diferi\u0163ilor factori externi (forma pere\u0163ilor, supapa, geometria pistonului etc.) asupra debitului de combustibil care circul\u0103 la un moment dat prin echipamentul de injec\u0163ie.<\/p>\n<p>Pe baza celor prezentate este posibil\u0103 determinarea c\u00e2mpurilor de presiune \u015fi de viteze \u00een \u00eentreg spa\u0163iul de curgere al motorinei (de la injector p\u00e2n\u0103 la pomp\u0103), ceea ce permite analizarea influen\u0163elor constructive asupra curgerii carburantului.<\/p>\n<p>Pe l\u00e2ng\u0103 debitul produs de injector, modelul permite analiza debitului de motorin\u0103 \u00een diferite sec\u0163iuni, pornind de la pistonul pompei, pe l\u00e2ng\u0103 supapa de refulare, prin conducta de \u00eenalt\u0103 presiune \u015fi p\u00e2n\u0103 la injector.<\/p>\n<p>Bibliografie:<br \/>\nOroveanu, T.: Mecanica fluidelor v\u00e2scoase, Editura Academiei, Bucure\u015fti, 1967.<br \/>\nHinze, O.: Turbulence, McGraw-Hill, 1975.<br \/>\nAram\u0103, C.: Instala\u0163ii pentru alimentarea cu combustibil a motoarelor cu ardere intern\u0103, Editura Tehnic\u0103, Bucure\u015fti,1966.<br \/>\nP\u0103r\u0103\u015fcioiu, C.: Optimizarea automat\u0103 a arderii combustibililor \u00een cuptoare tubulare, Tez\u0103 de doctorat, Universitatea Petrol-Gaze, Ploie\u015fti, 1994.<br \/>\nManea, A.: Determinarea rezistentei hidraulice a conductei pomp\u0103 injector din sistemul de alimentare cu combustibil al motorului diesel,Construc\u0163ia de Ma\u015fini, 24, 9, 1972.<br \/>\nStockner, A. R.; Flinn, M. A.; Camplin, F. A.: Development of the HEUI Fuel System-Integration of Design, Simulation, Test and Manufacturing, SAE Paper No. 930271, 1993.<br \/>\nStockner, A. R.; Flinn, M. A.; Camplin, F. A.: A New Direction for Diesel Engine Fuel System, SAE Paper No. 930270, 1993.<br \/>\nNeac\u015fu, S.: Studiul fenomenelor tranzitorii din circuitul de \u00eenalt\u0103 presiune al echipamentului de injec\u0163ie, Tez\u0103 de doctorat, Universitatea Petrol-Gaze, Ploie\u015fti, 1997.<\/p>\n<\/div><div class=\"special-heading-border\"><div class=\"special-heading-inner-border\"><\/div><\/div><\/div><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":3737,"comment_status":"open","ping_status":"closed","template":"","meta":{"footnotes":""},"tags":[],"portfolio_entries":[51],"class_list":["post-3736","portfolio","type-portfolio","status-publish","has-post-thumbnail","hentry","portfolio_entries-simularea-proceselor-hidrodinamice-din-echipamentul-de-injectie-al-motoarelor-diesel"],"_links":{"self":[{"href":"https:\/\/www.romconvert.ro\/new\/index.php\/wp-json\/wp\/v2\/portfolio\/3736","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.romconvert.ro\/new\/index.php\/wp-json\/wp\/v2\/portfolio"}],"about":[{"href":"https:\/\/www.romconvert.ro\/new\/index.php\/wp-json\/wp\/v2\/types\/portfolio"}],"author":[{"embeddable":true,"href":"https:\/\/www.romconvert.ro\/new\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.romconvert.ro\/new\/index.php\/wp-json\/wp\/v2\/comments?post=3736"}],"version-history":[{"count":2,"href":"https:\/\/www.romconvert.ro\/new\/index.php\/wp-json\/wp\/v2\/portfolio\/3736\/revisions"}],"predecessor-version":[{"id":3740,"href":"https:\/\/www.romconvert.ro\/new\/index.php\/wp-json\/wp\/v2\/portfolio\/3736\/revisions\/3740"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.romconvert.ro\/new\/index.php\/wp-json\/wp\/v2\/media\/3737"}],"wp:attachment":[{"href":"https:\/\/www.romconvert.ro\/new\/index.php\/wp-json\/wp\/v2\/media?parent=3736"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.romconvert.ro\/new\/index.php\/wp-json\/wp\/v2\/tags?post=3736"},{"taxonomy":"portfolio_entries","embeddable":true,"href":"https:\/\/www.romconvert.ro\/new\/index.php\/wp-json\/wp\/v2\/portfolio_entries?post=3736"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}