الملخص الانجليزى : The wedge and circular cross-sections of the combustion chamber are studied for the modeling of steady stateflow during the breathing stroke. The results could reveal certain conclusions which could be listed as follows; The total pressure drop difference between the two designs across the compartment during the breathing stoke is negligible. As the pressure drop ratio of WD to CD is less than 1.05 at Ncr= 3000 rpm.
The difference between mixing characteristics considering the secondary fluid flow parameters such as swirl number and vorticity is higher for the circular design. As the percentage reduction of J_abs^n and S for WD compared to CD at Ncr =3000 rpm were found to be 14.04% and 75.57%, respectively.
The wedged design presents a more compact design with less weight for the same displacement volume and reveals similar values associated with some performance characteristics. On the other hand, it exhibited lower values considering performance characteristics of the secondary flow.
Future studies could be directed in the combustion characteristics and the transient analysis of different strokes to reveal the feasibility of this design and increase compactness without sacrificing the performance characteristics. الملخص العربى : تم مقارنة خصائص التدفق في الحالة المستقرة لغرف محرک احتراق داخلي ذات مقطاع دائرية وإسفينية الشکل خلال شوط السحب. تمت دراسة أثر تقليل نصف القطر المحدب لتصميم الإسفين مقارنة بالتصميم الدائري على معاملات التدفق الأولية والثانوية مثل معامل انخفاض الضغط (زيادة بنسبة 0.05٪) ومعامل رقم الدوامة (انخفاض بنسبة 14.04٪) ومعامل شدة الدوامة الثانوية (انخفاض بنسبة 75.57٪). وقد کشفت النتائج عن الحاجة إلى مزيد من الدراسة لتحسين غرف الاحتراق عن طريق خفض حجمها الکلي.