nusselt number

简明释义

努谢尔特数

英英释义

例句

1.A higher Nusselt number 努塞尔数 indicates more efficient convective heat transfer.

较高的Nusselt number 努塞尔数 表示对流热传递更有效。

2.The Nusselt number 努塞尔数 plays a crucial role in thermal engineering applications.

Nusselt number 努塞尔数 在热工程应用中起着关键作用。

3.In this experiment, we observed how the Nusselt number 努塞尔数 changes with varying flow rates.

在这个实验中，我们观察了不同流速下Nusselt number 努塞尔数的变化。

4.The calculation of the Nusselt number 努塞尔数 is essential for determining heat transfer in fluid flow.

计算Nusselt number 努塞尔数 对于确定流体流动中的热传递至关重要。

5.We used empirical correlations to estimate the Nusselt number 努塞尔数 for our calculations.

我们使用经验相关关系来估算我们的计算中的Nusselt number 努塞尔数。

作文

The concept of the Nusselt number is essential in the field of heat transfer and fluid mechanics. Named after the German engineer Wilhelm Nusselt, this dimensionless number provides a measure of the convective heat transfer relative to conductive heat transfer across a boundary. Understanding the Nusselt number is crucial for engineers and scientists who deal with thermal systems, as it helps in predicting how effectively heat will be transferred in various conditions.In essence, the Nusselt number is defined as the ratio of convective to conductive heat transfer. When analyzing a system, if we know the thermal conductivity of the fluid and the temperature gradient, we can calculate the heat transfer through conduction. However, in most practical scenarios, especially in fluids, convection plays a significant role. This is where the Nusselt number comes into play, providing a way to quantify this effect.The Nusselt number is often used in conjunction with the Reynolds number and the Prandtl number, which together describe the flow characteristics of the fluid. The Reynolds number indicates the flow regime (laminar or turbulent), while the Prandtl number relates the momentum diffusivity to thermal diffusivity. By understanding these relationships, one can predict the behavior of heat transfer in different fluid flow situations.For laminar flow over a flat plate, the Nusselt number can be calculated using empirical correlations. For instance, in a situation where the flow is fully developed, the Nusselt number can be expressed as a constant value, depending on the flow conditions. In contrast, turbulent flows present a more complex scenario, as the Nusselt number can vary significantly based on the flow speed, temperature, and other factors.One common application of the Nusselt number is in the design of heat exchangers, which are critical in many industrial processes. Engineers use the Nusselt number to optimize the performance of these systems by ensuring that heat is transferred efficiently between fluids. By calculating the Nusselt number, they can determine the required surface area for effective heat exchange, ultimately leading to energy savings and improved efficiency.Moreover, the Nusselt number is not limited to just engineering applications. It also finds its relevance in environmental studies, such as understanding heat transfer in natural bodies of water or atmospheric conditions. For example, researchers may study the Nusselt number to analyze how heat is transferred from the sun to the ocean, impacting weather patterns and climate change.In conclusion, the Nusselt number is a fundamental aspect of heat transfer analysis that bridges the gap between conduction and convection. Its ability to quantify the efficiency of heat transfer in various scenarios makes it a vital tool for engineers, scientists, and researchers alike. By mastering the Nusselt number, one can gain insights into optimizing thermal systems, enhancing energy efficiency, and contributing to advancements in technology and environmental science.

Nusselt number（努塞尔数）是热传递和流体力学领域中的一个重要概念。它以德国工程师威廉·努塞尔的名字命名，表示对流热传递相对于通过边界的导热传递的量度。理解Nusselt number对于处理热系统的工程师和科学家至关重要，因为它有助于预测在各种条件下热量的有效传递。从本质上讲，Nusselt number定义为对流与导热的比率。当分析一个系统时，如果我们知道流体的热导率和温度梯度，就可以计算通过导热的热量传递。然而，在大多数实际情况下，尤其是在流体中，对流起着重要作用。这就是Nusselt number发挥作用的地方，它提供了一种量化这一效应的方法。Nusselt number通常与雷诺数和普朗特数一起使用，这三者共同描述流体的流动特性。雷诺数指示流动状态（层流或湍流），而普朗特数则将动量扩散与热扩散相关联。通过理解这些关系，可以预测不同流体流动情境下的热传递行为。对于平板上的层流，Nusselt number可以通过经验关联进行计算。例如，在流动完全发展的情况下，Nusselt number可以表示为一个常数值，具体取决于流动条件。相比之下，湍流则呈现出更复杂的情况，因为Nusselt number可能会根据流速、温度和其他因素显著变化。Nusselt number的一个常见应用是在热交换器的设计中，热交换器在许多工业过程中至关重要。工程师利用Nusselt number来优化这些系统的性能，确保热量在流体之间有效传递。通过计算Nusselt number，他们可以确定有效热交换所需的表面积，从而最终实现节能和提高效率。此外，Nusselt number不仅限于工程应用。它在环境研究中也有其相关性，例如理解自然水体或大气条件下的热传递。例如，研究人员可能会研究Nusselt number以分析太阳如何将热量传递给海洋，从而影响天气模式和气候变化。总之，Nusselt number是热传递分析的基本方面，它架起了导热与对流之间的桥梁。它能够量化各种情境下热传递的效率，使其成为工程师、科学家和研究人员的重要工具。通过掌握Nusselt number，人们可以深入了解如何优化热系统，提高能源效率，并推动技术和环境科学的发展。