Name: newtonian vs non-newtonian fluid behavior
Uploaded: 2025-02-13T15:43:08.000Z
Duration: 1 min 27 s
Channel: JoVE

تصنف السوائل إلى نوعين رئيسيين: نيوتن وغير نيوتني. تتمتع سوائل نيوتن بلزوجة ثابتة ، ويرتبط إجهاد القص خطيا بمعدل إجهاد القص.
يمكن التنبؤ بسلوك السوائل النيوتونية. تشمل الأمثلة الماء والهواء والزيت والبنزين.
ومع ذلك ، تظهر السوائل غير النيوتونية لزوجة متفاوتة بناء على معدل القص. وهي مقسمة إلى بلاستيك القص ، وسماكة القص ، وبلاستيك بينغهام.
تظهر سوائل ترقق القص ، مثل طلاء اللاتكس ومحاليل البوليمر ، لزوجة ظاهرية منخفضة مع زيادة معدل القص ، مما يسمح لها بالتدفق بسهولة أكبر عند القص.
هذه الخاصية مفيدة في تطبيقات مثل الطلاء بالفرشاة والطباعة النافثة للحبر ، حيث يلزم التطبيق السلس والمتساوي.
تظهر سوائل سماكة القص ، مثل نشا الذرة في الماء ، زيادة اللزوجة الظاهرة في ظل معدلات قص أعلى وتصبح أكثر مقاومة للتدفق عند التقليب.
هذه الخاصية الفريدة تجعلها مفيدة في معدات الحماية وأجهزة التخميد.
تتصرف بلاستيك بينغهام ، مثل معجون الأسنان والمايونيز ، كمواد صلبة بمجرد تجاوز إجهاد المحصول ، ثم تتدفق مثل السوائل ، مما يجعلها مثالية للمنتجات التي تحتاج إلى البثق أو الانتشار.

أنواع الموائع.

Types of Fluids

<div style="direction:rtl">يمكن تصنيف الموائع إلى موائع نيوتنية وغير نيوتنية بناءً على استجابتها لإجهاد القص. وفقًا لقانون اللزوجة لنيوتن فأنه للموائع النيوتونية علاقة خطية بين إجهاد القص ومعدل التشوه،. وتظل لزوجتها ثابتة بغض النظر عن معدل القص، مما يسهل من توقع وتحليل سلةكها. تشمل الأمثلة الشائعة الماء والهواء والنفط والبنزين. على النقيض من ذلك، لا تتبع الموائع الغير نيوتونية قانون اللزوجة لنيوتن، حيث تتغير لزوجتها مع تغير معدلات القص . يمكن تقسيم هذه الموائع إلى موائع تقل لزوجتها مع القص، وموائع تزيد لزوجتها مع القص، وموائع بينغهام البلاستيكية. تتناقص لزوجة الموائع التي تقل لزوجتها مع القص، والمعروفة أيضًا بالموائع الشبه بلاستيكية، مع زيادة معدل القص. تشمل الأمثلة طلاء اللاتكس ومحاليل البوليمر، والتي تتدفق بسهولة أكبر عند تعرضها للقوة، مما يجعلها مفيدة في التطبيقات التي تتطلب الانتشار السهل تحت تأثير الضغط. من ناحية أخرى، تزداد لزوجة موائع التي تزيد لزوجتها مع القص مع زيادة معدل القص. ومن الأمثلة الشائعة على ذلك خليط نشا الذرة والماء، الذي يصبح أكثر مقاومة للتدفق عند تحريكه، حيث يتسبب الضغط في حدوث مقاومة أكبر. تظهر موائع بينغهام البلاستيكية سلوكًا مختلفًا؛ فهي تعمل كمواد صلبة حتى يتم تطبيق إجهاد خضوع بقيمة محددة، بعد ذلك تتدفق مثل الموائع. تشمل الأمثلة معجون الأسنان والمايونيز، اللذين يقاومان الإجهاد الأولي ولكنهما يبدآن في التدفق بمجرد تجاوز إجهاد الخضوع. يساعد فهم هذه الأنواع من الموائع بشكل كبير في تصميم وتحليل أنظمة الموائع المختلفة، من خطوط الأنابيب إلى العمليات الصناعية، وضمان كفاءتها وعملها بشكل مناسب.</div>

تصنف السوائل إلى نوعين رئيسيين: نيوتن وغير نيوتني. السوائل النيوتونية لها لزوجة ثابتة ، وإجهاد القص خطيا ...

Education

JoVE Core

Civil Engineering

الهندسة المدنية

Unit 1

الوحدة الأولى

Fluid Properties

خصائص الموائع

KEY TERMS AND CONCEPTS

المصطلحات والمفاهيم الأساسية

newtonian vs non-newtonian fluid behavior

Fluids can be grouped by how they respond to shear stress. Shear stress is a force that acts across a material, and shear strain rate describes how quickly it changes shape or flows. In this lesson, fluids are divided into Newtonian and non-Newtonian types.

Newtonian fluids follow Newton’s law of viscosity. Their shear stress changes in a linear way as the shear rate changes. That means their viscosity stays constant, so their flow is predictable and easier to analyze. Water, air, oil, and gasoline are common examples.

Non-Newtonian fluids do not follow Newton’s law of viscosity. Their viscosity changes when the shear rate changes. These fluids are often grouped into shear-thinning, shear-thickening, and Bingham plastics.

Shear-thinning fluids are also called pseudoplastic fluids. Their viscosity decreases as the shear rate increases, so they flow more easily under force. Latex paint and polymer solutions are examples, and this makes them useful when a material needs to spread easily.

Shear-thickening fluids behave in the opposite way. Their viscosity increases as the shear rate increases, so they resist flow more when they are agitated. A cornstarch-water mixture is a common example.

Bingham plastics have another pattern. They act like solids until a certain yield stress is reached. After that, they begin to flow like fluids. Toothpaste and mayonnaise are examples, and they resist initial stress before they start moving.

Knowing these fluid behaviors helps in many real systems. It supports the design and analysis of pipelines and industrial processes. It also helps engineers choose the right fluid for efficient and reliable function.

Newtonian vs Non-Newtonian Fluid Behavior

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Fluids include liquids and gases, and they behave differently from solids because of how their molecules are arranged. In solids, molecules are tightly packed and held by strong intermolecular forces. That structure helps solids keep their shape and resist deformation. Fluids have molecules that are farther apart and held by weaker forces. Because of this, they can flow and change shape easily. A fluid is any substance that deforms continuously when shearing stress is applied. Shearing stress...

density, specific weight, specific gravity and compressibility of fluid

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Fluid Properties: Density, Weight and Compression

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Viscosity describes how much a fluid resists flow and deformation. It comes from internal friction between fluid layers that move past each other. Dynamic viscosity, shown by the Greek letter mu (μ), measures the force needed to move one layer over another. Newtonian fluids, such as water and air, have a linear relationship between shearing stress and the rate of shearing strain. Their viscosity stays constant, even when the applied stress changes. Non-Newtonian fluids, like ketchup,...

types of fluids

Fluids can be grouped by how they respond to shear stress. Shear stress is a force that acts across a material, and shear strain rate describes how quickly it changes shape or flows. In this lesson, fluids are divided into Newtonian and non-Newtonian types. Newtonian fluids follow Newton’s law of viscosity. Their shear stress changes in a linear way as the shear rate changes. That means their viscosity stays constant, so their flow is predictable and easier to analyze. Water, air, oil, and...

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Newtonian Fluid Viscosity and Shear Stress

Newtonian fluids have a constant viscosity, so their shear stress and shear strain rate stay directly proportional. This creates a linear, predictable link between force and flow. Water, air, and light oils are common examples of Newtonian fluids. A simple way to study this behavior is to place the fluid between two parallel plates. One plate stays still, and the other moves at a constant velocity. The fluid forms a velocity gradient, which is the change in speed across the distance between...

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Vapor Pressure and Boiling Behavior

Vapor pressure and boiling behavior are closely linked in fluids. Vapor pressure is the pressure a vapor exerts when it is in thermodynamic equilibrium with its liquid at a given temperature. It shows how strongly molecules tend to leave the liquid surface and move into the vapor phase. A closed container helps show how vapor pressure forms. If a liquid sits in a sealed space with a small air gap, and that space is evacuated, vapor molecules escape from the liquid into the empty space. The...

surface tension of fluid

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Capillary Action in Narrow Spaces

Capillary action is the movement of liquid through narrow spaces without any outside force. It depends on surface tension and adhesion between the liquid and nearby solid surfaces. This effect is common in narrow tubes, porous materials, and fine particles. Surface tension comes from cohesive forces between liquid molecules at the liquid-air boundary. These forces create a thin skin that resists outside pressure. When a capillary tube is placed in a liquid, the liquid level changes because of...

design example: deciding thickness of lubricating fluid in a shaft

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Lubricant Film Thickness for Shaft Bearings

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key terms and concepts

Learn how Newtonian and non-Newtonian fluids respond to shear stress, with examples of shear-thinning, shear-thickening, and Bingham plastics.

Newtonian vs Non-Newtonian Fluid Behavior | JoVE K12

JoVE Core Civil Engineering provides a foundational exploration of essential construction materials in civil engineering, focusing on bricks, stones, steel, wood, and concrete through easy-to-understand animated videos. This collection covers the properties, manufacturing processes, and practical applications of these materials. Additionally, the accompanied science-in-action videos demonstrate the research experiments performed in laboratories.

civil engineering

Newtonian vs Non-Newtonian Fluid Behavior

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