Name: how depth changes fluid pressure
Uploaded: 2023-09-22T11:49:33.000Z
Duration: 1 min 14 s
Channel: JoVE

يعرف الضغط بأنه حجم القوة لكل وحدة مساحة. بالنظر إلى سائل غير قابل للانضغاط ، يمكن التعبير عن القوة من حيث الوزن المحدد أو كثافة السائل.
ضع في اعتبارك أربع نقاط في الماء. الضغط هو نفسه لجميع النقاط على نفس العمق من السطح ، ولكن أقل في الأعماق الضحلة. يزداد الضغط خطيا مع العمق من السطح.
وفقا لقانون باسكال ، فإن شدة الضغط في أي نقطة معينة في سائل ثابت غير قابل للانضغاط هي نفسها في جميع الاتجاهات.
افترض عنصر سائل متناهي الصغر على شكل إسفين بعرض الوحدة. يتم التعبير عن القوة على كل جانب على أنها ناتج الضغط والمساحة.
نظرا لأن السائل في حالة راحة ، يجب أن يكون مجموع المكونات الأفقية والرأسية للقوى صفرا.
بأخذ المكونات الأفقية واستخدام العلاقات المثلثية ، يتم تبسيط المعادلات للحصول على px يساوي ps.
وبالمثل ، بالنظر إلى المكونات الرأسية ، يتم تبسيط المعادلات للحصول على py يساوي ps. 
إذن، الضغط في أي وقت هو نفسه في جميع الاتجاهات.

<ol>
	<li>هيبلر ، آر سي (2016). الميكانيكا الهندسية: الإحصاء. الطبعة الرابعة عشرة ، نيو جيرسي: بيرسون. ص 512.</li>
</ol>

ضغط السوائل

<div style="direction:rtl">في الهندسة الميكانيكية، يعد ضغط السوائل أمرًا حيويًا في تصميم الأنظمة التي تعتمد على تدفق السوائل، مثل الأنظمة الهيدروليكية، المضخات، والصمامات. عند تصميم هذه الأنظمة، يجب على المهندسين التأكد من قدرتها على تحمل القوى الناتجة عن ضغط السائل، وذلك لتفادي حدوث أي تلف أو فشل. ووفقًا لقانون باسكال، فإن السائل الساكن يولد ضغطًا متساويًا في جميع الاتجاهات. يتم قياس هذا الضغط كوحدة قوة لكل وحدة مساحة، ويعتمد على وزن السائل النوعي أو كثافته الكتلية وعمق نقطة القياس من سطح السائل. يمكننا التعبير عن هذه العلاقة رياضيًا بالصيغة p = ρgz، حيث ρ هي كثافة السائل، وg هو تسارع الجاذبية، وz هو العمق. يجب الإشارة إلى أن المعادلة المذكورة أعلاه صحيحة للسوائل غير القابلة للضغط، مثل معظم السوائل، ولكنها ليست صحيحة بالنسبة للغازات، حيث تتغير كثافتها بشكل كبير مع التغيرات في درجة الحرارة والضغط. لفهم كيفية تطبيق هذه المعادلة على السوائل، قم بمراجعة ثلاث نقاط داخل الماء. عند نفس العمق من السطح، يكون الضغط متساويًا في جميع النقاط الثلاث. ومع ذلك، يكون الضغط أقل في الأعماق الضحلة، ويزداد الضغط بشكل خطي مع العمق عند التوجه بعيدًا عن السطح.</div>

في الهندسة الميكانيكية ، يلعب ضغط السوائل دورا مهما في تصميم الأنظمة التي تستخدم تدفق السائل ، مثل الأنظمة الهيدروليكية والمضخات و ...

Education

JoVE Core

Mechanical Engineering

الهندسة الميكانيكية

Unit 1

الوحدة الأولى

Center of Gravity and Centroid

مركز الثقل والمركز الهندسي

KEY TERMS AND CONCEPTS

المصطلحات والمفاهيم الأساسية

Fluid Pressure

how depth changes fluid pressure

Fluid pressure changes with depth in liquids used in engineering systems. It matters in hydraulic systems, pumps, and valves, where the forces from moving and resting fluid must be considered to prevent damage or failure.

For a fluid at rest, Pascal’s law says the pressure is equal in all directions. Pressure is force per unit area. Its size depends on the fluid’s specific weight, or mass density, and on how deep the measurement point is below the fluid surface.

This relationship can be written as p = ρgz. In this equation, ρ is fluid density, g is the acceleration due to gravity, and z is depth. The equation applies to incompressible fluids, such as most liquids, but not to gases, because gas density can change greatly with temperature and pressure.

The pattern is easy to see in water. If three points are at the same depth, their pressure is the same. A point closer to the surface has lower pressure. As depth increases, pressure rises in a linear way.

How Depth Changes Fluid Pressure

center of gravity

Center of Gravity in Balance and Design

The center of gravity is the point where an object’s weight appears to act. It is the spot used to balance the object most evenly. In mechanics, this point helps explain stability and moments of inertia. The center of gravity does not always sit inside the object’s shape. In some cases, it can lie outside the body. That is why the idea is useful for both simple and more complex shapes. Its location can be found with the principle of moments. The object is divided into very small parts, and...

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Finding the Center of a Body

The centroid is the geometric center of a body. It is an important idea in engineering, physics, and mechanics. For many objects, it lies inside the body. A body with holes or cavities can be an exception. For a homogeneous body, the centroid matches the center of mass or the center of gravity. Homogeneous means the material has a uniform density. In that case, the centroid can often be found by balancing the moments of the body’s volume. Symmetry can also help locate the centroid. If a...

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Centroid of a Quarter Circle Wire

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The centroid of a paraboloid of revolution is the point where its mass is balanced. A paraboloid of revolution is an axially symmetric surface made by rotating a parabola around its axis. In engineering, this location matters because it helps show how forces spread across the shape. Knowing the centroid can help when building parts that must handle stress and pressure reliably. The paraboloid shape has useful structural properties, including rotational symmetry and strength against stress...

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Center of Gravity in Composite Bodies

Composite bodies are made of multiple connected parts that act as one larger object. Each part still has its own weight and center of gravity. To find the center of gravity of the whole body, engineers must account for every part. When the density or specific weight is constant, the center of gravity matches the centroid. The centroid is the geometric center of a shape. This idea is useful when analyzing parts that behave as a single unit. Composite bodies are common in mechanical engineering.

theorems of pappus and guldinus

Surface Area and Volume by Centroid Paths

Pappus and Guldinus theorems help find the surface area and volume of bodies of revolution. A body of revolution is formed when a plane curve or plane area is turned around an axis that does not intersect it. For surface area, a curve is revolved around a non-intersecting axis. A small line element on the curve creates a thin ring as it moves. Adding these ring areas gives the total surface area of the solid. The first theorem says that this surface area equals the length of the generating...

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Pappus and Guldinus Theorems for Surface Area

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Distributed loads create a force that is spread over a surface instead of acting at one point. To analyze this kind of loading, engineers use a single resultant force. That force represents the net effect of the entire load. This idea is important in structures that face non-uniform loads. Wind can push on buildings and towers with changing speed and direction, so the load is not evenly spread. Bridges also experience non-uniform loading from vehicles, and some parts of the bridge can feel...

fluid pressure

Fluid pressure changes with depth in liquids used in engineering systems. It matters in hydraulic systems, pumps, and valves, where the forces from moving and resting fluid must be considered to prevent damage or failure. For a fluid at rest, Pascal’s law says the pressure is equal in all directions. Pressure is force per unit area. Its size depends on the fluid’s specific weight, or mass density, and on how deep the measurement point is below the fluid surface. This relationship can be...

fluid pressure over flat plate of constant width

fluid-pressure-over-flat-plate-of-constant-width

Center of Pressure on a Submerged Plate

Fluid pressure on a submerged flat plate depends on depth and shape. A plate under water experiences pressure acting normal to its surface, and the force is spread across the whole area. For a rectangular plate of constant width, this pressure increases from the top edge to the bottom edge. Because the pressure rises with depth, the loading forms a trapezoidal distribution. The resultant force on the plate comes from the trapezoidal volume of water with a specific weight. The line of action of...

fluid pressure over curved plate of constant width

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fluid pressure over flat plate of variable width

fluid-pressure-over-flat-plate-of-variable-width

A submerged flat plate experiences fluid pressure that changes with depth. This pressure can create effects such as drag and buoyancy. To study a flat plate with variable width, the pressure distribution across the plate must be analyzed first. The force on a small strip of the plate is found by multiplying the pressure by the strip’s differential area. The pressure can also be written using the fluid’s specific weight and the depth of that strip below the surface. To find the total, or...

key terms and concepts

Explore how fluid pressure changes with depth, why Pascal’s law matters, and how the equation p = ρgz describes pressure in liquids like water.

How Depth Changes Fluid Pressure | JoVE K12

JoVE Core Mechanical Engineering offers concise, easy-to-understand animated videos covering key topics such as equilibrium, forces, truss analysis, and structural mechanics. Explore their real-world applications, and witness these concepts in action through scientist-led experiments.

mechanical engineering

How Depth Changes Fluid Pressure

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