Thesis (M.Sc)-Cairo University, 2025.

Bibliography: pages 44-48.

In this research, a new design of "orifice plate" is developed to allow for energy
dissipation with a low probability of clogging. The impact of changing the hydraulic and
geometrical parameters of the orifice plate on the head loss coefficient is experimentally
investigated. The head loss coefficients for the different opening ratios of the proposed
orifice plates are obtained. The effect of using multistage orifice plates on the head loss
coefficient is also investigated. Results show that the head loss coefficient remains
unchanged for flows with Reynolds numbers (Re > 105), which is the operating condition
for most steep-slope pipelines. The head loss coefficient was found to be 5.11, 2.48, 1.50,
and 0.81 for opening ratios of 0.50, 0.60, 0.70, and 0.80, respectively. In the case of
multistage orifices, the head loss coefficient remained unchanged compared to that for a
single orifice as long as the orifices are spaced by 10 D and the total head loss coefficient
for this configuration equals the head loss coefficient for a single orifice times the number
of orifices in the configuration. This configuration can be utilized to create multiple local
losses along the pipeline to gradually dissipate the required head and reduce the
probability of cavitation.

تم استحداث تصميم جديد للألواح المثقوبة لتشتيت الطاقة مع تقليل احتمالات الانسداد. أُجريت دراسة معملية لتحليل تأثير العوامل الهيدروليكية وأشكال الألواح على معامل فقدان الطاقة. أظهرت النتائج أن معامل الفقد لا يتأثر برقم رينولدز عندما يكون Re > 1×10⁵. كما تبين أن معامل الفقد يبلغ 5.11 و2.48 و1.50 و0.81 لنسب الفتح 50%-60%-70%-80% على التوالي. عند استخدام عدة ألواح متتالية، يكون الفقد الكلي مساويًا لمعامل فقد اللوح الواحد مضروبًا في عدد الألواح. يتيح هذا الترتيب تشتيت الطاقة تدريجيًا وتقليل خطر التكهف في خطوط الأنابيب شديدة الانحدار.

Issues also as CD.

Text in English and abstract in Arabic & English.