prandtl number

简明释义

普朗特数

英英释义

例句

1.A low prandtl number suggests that a fluid will have a high thermal conductivity relative to its viscosity.

低普朗特数表明一种流体相对于其粘度具有高热导率。

2.The flow characteristics of the fluid can be analyzed using the prandtl number, which indicates the ratio of momentum diffusivity to thermal diffusivity.

流体的流动特性可以通过普朗特数进行分析，它表示动量扩散率与热扩散率的比率。

3.The prandtl number is particularly important in the study of boundary layers in fluid mechanics.

普朗特数在流体力学的边界层研究中特别重要。

4.When simulating airflow over an aircraft wing, engineers must consider the prandtl number for accurate results.

在模拟飞机机翼上的气流时，工程师必须考虑普朗特数以获得准确的结果。

5.In heat exchanger design, the prandtl number plays a crucial role in determining the heat transfer efficiency.

在热交换器设计中，普朗特数在确定热传递效率方面起着至关重要的作用。

作文

The concept of the Prandtl number is fundamental in the field of fluid dynamics and heat transfer. It is a dimensionless number that characterizes the relative thickness of the momentum and thermal boundary layers in a fluid flow. The Prandtl number, often denoted by the symbol Pr, is defined as the ratio of kinematic viscosity to thermal diffusivity. In mathematical terms, it can be expressed as: Pr = ν / α, where ν represents the kinematic viscosity and α denotes the thermal diffusivity. This relationship is crucial for understanding how fluids behave under various thermal conditions.In practical applications, the Prandtl number helps engineers and scientists predict the heat transfer characteristics of different fluids. For instance, when analyzing the cooling of a heated surface, knowing the Prandtl number allows one to determine whether convection or conduction will dominate the heat transfer process. Fluids with a low Prandtl number, such as mercury, tend to have a thinner thermal boundary layer, which means they can conduct heat more effectively compared to fluids with a high Prandtl number, like oils. This distinction is vital in designing systems for efficient thermal management.Moreover, the Prandtl number also plays a significant role in various engineering applications, including HVAC systems, chemical reactors, and heat exchangers. For example, in the design of heat exchangers, engineers must consider the Prandtl number to optimize the exchange of heat between two fluids. A proper understanding of this number can lead to more efficient designs, reduced energy consumption, and improved system performance.Additionally, the Prandtl number can vary significantly between different fluids and under different conditions. For instance, when dealing with air at room temperature, the Prandtl number is typically around 0.71, indicating a relatively balanced relationship between momentum and thermal transport. However, in water, the Prandtl number is approximately 7, suggesting that thermal diffusion occurs much slower than momentum diffusion. Such variations highlight the importance of selecting the appropriate fluid for specific applications, especially in processes that require precise temperature control.In summary, the Prandtl number is a crucial parameter in the study of fluid dynamics and heat transfer. Its ability to characterize the relationship between momentum and thermal transport makes it an invaluable tool for engineers and scientists alike. Understanding the Prandtl number not only aids in predicting fluid behavior but also enhances the efficiency of thermal systems across various industrial applications. As technology continues to advance, the importance of accurately calculating and applying the Prandtl number will only grow, reinforcing its status as a key concept in thermodynamics and fluid mechanics.

普朗特数（Prandtl number）的概念在流体动力学和热传递领域中是基础性的。它是一个无量纲数，表征流体流动中动量边界层和热边界层的相对厚度。Prandtl number通常用符号Pr表示，定义为运动粘度与热扩散率的比率。在数学上，它可以表示为：Pr = ν / α，其中ν代表运动粘度，α表示热扩散率。这种关系对于理解流体在不同热条件下的行为至关重要。在实际应用中，Prandtl number帮助工程师和科学家预测不同流体的热传递特性。例如，在分析加热表面的冷却时，了解Prandtl number可以确定对流或导热在热传递过程中的主导作用。低Prandtl number的流体，如汞，往往具有较薄的热边界层，这意味着它们能够更有效地导热，而高Prandtl number的流体，如油，则相反。这种区别在设计高效热管理系统时至关重要。此外，Prandtl number在各种工程应用中也发挥着重要作用，包括暖通空调系统、化学反应器和热交换器。例如，在热交换器的设计中，工程师必须考虑Prandtl number以优化两个流体之间的热交换。对这一数值的正确理解可以导致更高效的设计、降低能耗和改善系统性能。另外，Prandtl number在不同流体和不同条件下可能会有显著变化。例如，在室温下处理空气时，Prandtl number通常约为0.71，表明动量和热传输之间的关系相对平衡。然而，在水中，Prandtl number约为7，表明热扩散发生得远比动量扩散慢。这种变化突显了选择适当流体以满足特定应用的重要性，尤其是在需要精确温度控制的过程中。总之，Prandtl number是流体动力学和热传递研究中的关键参数。它能够表征动量和热传输之间的关系，使其成为工程师和科学家不可或缺的工具。理解Prandtl number不仅有助于预测流体行为，还提高了各类工业应用中热系统的效率。随着技术的不断进步，准确计算和应用Prandtl number的重要性将日益增长，进一步巩固其在热力学和流体力学中的关键地位。