Low-temperature combustion modes have attracted global attention in recent years, especially the homogeneous charge compression ignition (HCCI) mode. The HCCI produces high-speed combustion, achieving relatively high thermal efficiencies while emitting low NOX and soot. However, due to lack of direct control start one main challenges this type engine is ensure that auto-ignition occurs close to...

شرایط افروزش و اشتعال سوخت‌های گداخت هسته‌ای در حضور ناخالص­‌ها، یکی از موارد مهمی است که طراحی قرص‌های سوخت باید مورد توجه قرار گیرد. این مقاله اثر ناخالصی هسته سنگین طلا بر کلیه فرایندهای احتراق پلاسمای غیرتعادلی دوتریم- تریتیم مدل چهار دمایی آن شکل تابع توزیع انرژی رفتار فوتون‌ها تأثیر می‌گذارد بررسی گرفته است. مطالعه شامل اثرات منفی سوخت، طول زمان تشکیل لکه داغ نتایج محاسبات عددی به­ دست آم...

  This paper presents a modeling study of a CNG Homogenous Charge Compression Ignition (HCCI) engine using single-zone and multi-zone combustion models. Authors' developed code could be able to predict engine combustion and performance parameters in closed part of the engine cycle. As detailed chemical kinetics is necessary to investigate combustion process in HCCI engines, therefore, GRI-m...

New HCCI/CAI Combustion Process Development: Methodology for Determination of Relevant Fuel Parameters — To pass the simultaneous emission requirements for near zero pollutant and low CO2 levels, which are the challenges for future powertrains, many research studies are currently carried out over the world on new engine combustion processes, such as controlled auto-ignition (CAITM) for gasoline...

in order to comply with stringent pollutant emissions regulations, a detailed analysis of the engine combustion and emission is required. in this field, computational tools like cfd and engine cycle simulation play a fundamental role. therefore, the goal of the present work is to simulate a high speed di diesel engine and study the combustion and major diesel engine emissions with more details,...

This study examines the possibility to provide control over ignition timing in a homogeneous charge compression engine (HCCI) using fuel additive whose molecular structure can be adapted upon exposure UV light. The molecule has greater influence on retarding than original molecule, hence time modulated expose new is referred as ‘smart fuel’. form of 1,3-cyclohexadiene (CHD), it undergoes electr...

Homogenous charge compression ignition (HCCI) combustion is spontaneous multi-site combustion of a nominally premixed air/fuel mixture that exhibits high rate of pressure rise and short combustion duration. To avoid excessive pressure rise rate and knocking, HCCI engines are fueled with highly diluted mixture using a combination of excess air and/or EGR. HCCI combustion is attractive due to ...

in this paper, the performance of a natural gas hcci engine is studied through a thermodynamic model including detailed chemical kinetics. it is shown that as hydroxyl radical has important effects on natural gas combustion, it is possible to quantify soc with hydroxyl concentration variations. meanwhile the influence of using formaldehyde as an additive on the engine characteristics has been i...

in this study, an in-house multi-dimensional code has been developed which simulates the combustion of n-heptane in a homogeneous charge compression ignition (hcci) engine. it couples the flow field computations with detailed chemical kinetic scheme which involves the multi-reactions equations. a chemical kinetic scheme solver has been developed and coupled for solving the chemical reactions an...