h = Nu × k/L = 250.3 × 0.025 W/m·K / 1 m = 6.26 W/m^2·K
h = Nu × k/D = 421.1 × 0.025 W/m·K / 0.1 m = 105.3 W/m^2·K
: A cylinder with a diameter of 0.1 m and a length of 1 m is exposed to a fluid flowing at a velocity of 10 m/s. The fluid has a temperature of 50°C and a kinematic viscosity of 2 × 10^(-5) m^2/s. Calculate the heat transfer coefficient and the Nusselt number. h = Nu × k/L = 250
Re = ρUD/μ = (1000 kg/m^3 × 10 m/s × 0.1 m) / (2 × 10^(-5) kg/m·s) = 50,000
Heat and mass transfer are fundamental concepts in engineering, playing a crucial role in the design and analysis of various systems, including heat exchangers, refrigeration systems, and drying processes. The book "Heat and Mass Transfer" by Yunus Cengel is a widely used textbook in engineering courses, providing a comprehensive introduction to the principles of heat and mass transfer. In this article, we will focus on the solution manual for Chapter 7 of the 5th edition of Cengel's book, covering the topic of external forced convection. Re = ρUD/μ = (1000 kg/m^3 × 10 m/s × 0
External forced convection occurs when a fluid flows over a surface, driven by an external agent such as a fan or a pump. This type of convection is commonly encountered in various engineering applications, including heat exchangers, electronic cooling systems, and wind turbines. In Chapter 7 of Cengel's book, the author provides an in-depth analysis of external forced convection, covering topics such as the velocity and thermal boundary layers, laminar and turbulent flow, and the calculation of heat transfer coefficients.
Nu = 0.026 × Re^0.8 × Pr^0.33 = 0.026 × (50,000)^0.8 × 2.58^0.33 = 421.1 External forced convection occurs when a fluid flows
: Using the solution manual, we can find the solution to this problem. First, we calculate the Reynolds number: