dimensionless number

简明释义

无量纲值

英英释义

例句

1.In heat transfer analysis, the Nusselt number is a crucial dimensionless number indicating the ratio of convective to conductive heat transfer.

在热传递分析中，努塞尔数是一个关键的无量纲数，表示对流与导热的比率。

2.The Froude number is a dimensionless number that compares inertial and gravitational forces in fluid mechanics.

弗劳德数是一个无量纲数，用于比较流体力学中的惯性力和重力。

3.The Strouhal number is used in fluid dynamics to characterize oscillating flow mechanisms and is a dimensionless number.

斯特劳哈尔数用于流体动力学，以表征振荡流动机制，是一个无量纲数。

4.The Reynolds number is a key dimensionless number that helps predict flow patterns in different fluid flow situations.

雷诺数是一个关键的无量纲数，它有助于预测不同流体流动情况中的流动模式。

5.When analyzing the performance of a chemical reactor, the Damköhler number is an important dimensionless number.

在分析化学反应器的性能时，达姆科勒数是一个重要的无量纲数。

作文

In the field of science and engineering, the concept of a dimensionless number plays a crucial role in understanding various phenomena. A dimensionless number is a quantity that has no units associated with it, meaning it is a pure number. This characteristic allows scientists and engineers to compare different systems without the complications introduced by varying units of measurement. For instance, the Reynolds number, which is a type of dimensionless number, helps predict flow patterns in different fluid flow situations. It is defined as the ratio of inertial forces to viscous forces and is calculated using the velocity of the fluid, its density, and its viscosity. By using this dimensionless number, one can determine whether the flow will be laminar or turbulent, which is essential for designing efficient systems in various engineering applications.Another important dimensionless number is the Mach number, which is used in aerodynamics to describe the speed of an object moving through a fluid compared to the speed of sound in that fluid. The Mach number is significant because it influences the behavior of the air around an aircraft. At subsonic speeds (Mach < 1), the airflow behaves differently than at supersonic speeds (Mach > 1). Thus, understanding the Mach number allows engineers to design aircraft that can operate efficiently across different flight regimes.The use of dimensionless numbers extends beyond fluid dynamics; they are also prevalent in heat transfer, chemical reactions, and other areas of physics and engineering. For example, the Nusselt number is a dimensionless number that indicates the ratio of convective to conductive heat transfer across a boundary. This number is vital for engineers when designing heat exchangers, as it helps them understand how effectively heat is transferred between fluids.Moreover, dimensionless numbers facilitate the process of scaling up experiments from laboratory settings to real-world applications. When conducting experiments, researchers often work with small-scale models. By using dimensionless numbers, they can ensure that the results obtained from these models can be applied to larger systems. This is particularly useful in fields like hydrodynamics, where understanding the behavior of water flow in a small channel can inform designs for large rivers or canals.In summary, dimensionless numbers are fundamental tools in the realms of science and engineering. They provide a means of comparison that transcends the limitations of units and scales, allowing for a more profound understanding of complex systems. Whether it’s predicting the behavior of fluids, designing efficient thermal systems, or scaling experimental results, dimensionless numbers are indispensable in the toolkit of scientists and engineers alike. Their ability to simplify complex relationships into understandable and comparable quantities makes them essential for innovation and discovery in numerous fields of study.

在科学和工程领域，无量纲数的概念在理解各种现象中起着至关重要的作用。无量纲数是一个没有单位相关的量，意味着它是一个纯数字。这一特性使得科学家和工程师能够在不同系统之间进行比较，而不必担心因测量单位的不同而引入的复杂性。例如，雷诺数就是一种无量纲数，它有助于预测不同流体流动情况下的流动模式。它被定义为惯性力与粘性力的比率，并通过流体的速度、密度和粘度来计算。通过使用这个无量纲数，人们可以确定流动是层流还是湍流，这对于设计各种工程应用中的高效系统至关重要。另一个重要的无量纲数是马赫数，它用于空气动力学中描述物体在流体中移动的速度与该流体中的声速的比率。马赫数的重要性在于它影响着飞机周围空气的行为。在亚音速（马赫数<1）时，气流的行为与超音速（马赫数>1）时不同。因此，理解马赫数使工程师能够设计出可以在不同飞行状态下高效运行的飞机。无量纲数的使用不仅限于流体动力学；它们在热传递、化学反应和其他物理及工程领域也很常见。例如，努塞尔数是一个无量纲数，表示对流与导热之间的比率。这个数值对于工程师在设计热交换器时至关重要，因为它帮助他们理解流体之间热量转移的有效性。此外，无量纲数促进了从实验室设置到现实世界应用的实验缩放过程。当进行实验时，研究人员通常会使用小规模模型。通过使用无量纲数，他们可以确保从这些模型中获得的结果可以应用于更大的系统。这在水力学等领域特别有用，理解小通道中水流的行为可以为大型河流或运河的设计提供信息。总之，无量纲数是科学和工程领域的基本工具。它们提供了一种超越单位和尺度限制的比较手段，使人们对复杂系统有更深刻的理解。无论是预测流体的行为、设计高效的热系统，还是缩放实验结果，无量纲数在科学家和工程师的工具箱中都是不可或缺的。它们将复杂关系简化为可理解和可比较的量，使它们在众多研究领域的创新和发现中至关重要。