dimensionless number

简明释义

无因次数

英英释义

例句

1.In heat transfer analysis, the Nusselt number is an important dimensionless number 无量纲数 that relates convective to conductive heat transfer.

在热传递分析中，努塞尔数是一个重要的无量纲数 dimensionless number，它将对流与导热传递联系起来。

2.The Reynolds number is a crucial dimensionless number 无量纲数 used to predict flow patterns in different fluid flow situations.

雷诺数是一个关键的无量纲数 dimensionless number，用于预测不同流体流动情况中的流动模式。

3.The Schmidt number is a dimensionless number 无量纲数 that describes the ratio of momentum diffusivity to mass diffusivity.

施密特数是一个描述动量扩散率与质量扩散率比值的无量纲数 dimensionless number。

4.The Strouhal number is used in fluid dynamics as a dimensionless number 无量纲数 that describes oscillating flow mechanisms.

斯特劳哈尔数在流体动力学中用作描述振荡流动机制的无量纲数 dimensionless number。

5.When analyzing the performance of a pump, engineers often refer to the specific speed, which is a dimensionless number 无量纲数 indicating the pump's efficiency.

在分析泵的性能时，工程师常常提到特定转速，这是一个表示泵效率的无量纲数 dimensionless number。

作文

In the field of science and engineering, the concept of a dimensionless number plays a crucial role in understanding various physical phenomena. A dimensionless number is a quantity that has no units associated with it, meaning it is a pure number that describes a relationship between different physical quantities. This characteristic makes dimensionless numbers incredibly useful for comparing different systems, as they allow for the simplification of complex equations and the identification of key parameters that govern the behavior of those systems.One of the most well-known examples of a dimensionless number is the Reynolds number, which is used in fluid mechanics to predict flow patterns in different fluid flow situations. The Reynolds number is calculated using the ratio of inertial forces to viscous forces, providing insight into whether the flow will be laminar or turbulent. This is particularly important in engineering applications, such as the design of aircraft wings or the analysis of blood flow in medical studies, where understanding the flow dynamics can lead to better designs and improved health outcomes.Another significant dimensionless number is the Mach number, which describes the speed of an object moving through a fluid compared to the speed of sound in that fluid. This number is critical in aerospace engineering, as it helps engineers determine whether an aircraft will operate subsonically, transonically, or supersonically. By using the Mach number, engineers can optimize designs to ensure stability and performance at various speeds, which is essential for safety and efficiency in aviation.The usefulness of dimensionless numbers extends beyond fluid mechanics and aerodynamics. In heat transfer, the Nusselt number is a dimensionless number that represents the ratio of convective to conductive heat transfer. This allows engineers to analyze thermal systems more effectively, whether it be in designing heat exchangers or assessing thermal insulation in buildings. Similarly, the Prandtl number, which relates the rate of momentum diffusion to the rate of thermal diffusion, is another example of how dimensionless numbers help simplify the analysis of complex heat transfer scenarios.Moreover, dimensionless numbers are not limited to classical physics; they also find applications in modern fields such as biology and environmental science. For instance, the dimensionless concentration ratio in biochemical reactions can help researchers understand the kinetics of enzyme reactions without the need for specific unit measurements. This ability to generalize results across different systems enhances the predictive power of scientific models.In conclusion, dimensionless numbers are indispensable tools in science and engineering that facilitate the comparison and analysis of different physical systems. Their lack of units allows for broader applicability and simplification of complex relationships, making them vital for both theoretical studies and practical applications. As technology continues to advance, the importance of dimensionless numbers will likely grow, leading to further innovations and discoveries across various disciplines. Understanding these numbers not only enriches our knowledge of the physical world but also empowers us to solve real-world problems more effectively.

在科学和工程领域，无量纲数的概念在理解各种物理现象中起着至关重要的作用。无量纲数是一个与单位无关的量，意味着它是一个纯数字，描述了不同物理量之间的关系。这一特性使得无量纲数在比较不同系统时极其有用，因为它们简化了复杂方程并识别出支配这些系统行为的关键参数。最著名的无量纲数之一是雷诺数，它用于流体力学中预测不同流体流动情况中的流动模式。雷诺数是通过惯性力与粘性力的比率计算得出的，提供了流动是层流还是湍流的洞察。这在工程应用中尤为重要，例如在飞机机翼设计或医学研究中分析血流，理解流动动态可以导致更好的设计和改善健康结果。另一个重要的无量纲数是马赫数，它描述了物体在流体中移动的速度与该流体中音速的比值。这个数字在航空工程中至关重要，因为它帮助工程师确定飞机是在亚音速、跨音速还是超音速下运行。通过使用马赫数，工程师可以优化设计，以确保在各种速度下的稳定性和性能，这对于航空的安全和效率至关重要。无量纲数的有用性不仅限于流体力学和空气动力学。在热传递中，努塞尔数是一个表示对流与导热比率的无量纲数。这使得工程师能够更有效地分析热系统，无论是在设计热交换器还是评估建筑物的热绝缘性。同样，普朗特数，它将动量扩散速率与热扩散速率联系起来，是另一个例子，说明了无量纲数如何帮助简化复杂的热传递场景的分析。此外，无量纲数不仅限于经典物理；它们还在现代生物学和环境科学等领域找到应用。例如，生化反应中的无量纲浓度比可以帮助研究人员理解酶反应的动力学，而无需特定的单位测量。这种在不同系统之间推广结果的能力增强了科学模型的预测能力。总之，无量纲数是科学和工程中不可或缺的工具，促进了不同物理系统的比较和分析。它们没有单位，使其具有更广泛的适用性并简化复杂关系，使其在理论研究和实际应用中都至关重要。随着技术的不断进步，无量纲数的重要性可能会增长，从而在各个学科中推动进一步的创新和发现。理解这些数字不仅丰富了我们对物理世界的知识，而且赋予我们更有效地解决现实问题的能力。