There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

The boundary layer equations for plane, incompressible, and steady flow are 

$$\matrix{ {u{{\partial u} \over {\partial x}} + v{{\partial u} \over {\partial y}} = - {1 \over \varrho }{{\partial p} \over {\partial x}} + v{{{\partial ^2}u} \over {\partial {y^2}}},} \cr {0 = {{\partial p} \over {\partial y}},} \cr {{{\partial u} \over {\partial x}} + {{\partial v} \over {\partial y}} = 0.} \cr }$$

Boundary Layer Theory

An introduction to heat transfer

Thank you very much for reading principles of enhanced heat transfer. As you may know, people have look numerous times for their chosen books like this principles of enhanced heat transfer, but end up in malicious downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they are facing with some infectious bugs inside their desktop computer. principles of enhanced heat transfer is available in our book collection an online access to it is set as public so you can get it instantly. Our books collection spans in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Merely said, the principles of enhanced heat transfer is universally compatible with any devices to read.

Principles Of Enhanced Heat Transfer

: The objective of this project is to improve our fundamental knowledge of turbulent flows over rough surfaces. Specifically, we hope to investigate the manner in which roughness affects the near-wall drag-producing turbulent structures, and to what extent surface roughness affects the outer part of rough-wall boundary layers. Ultimately we hope to use this knowledge to propose control strategies to reduce momentum loss in rough-wall boundary layers.

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA426193&Location=U2&doc=GetTRDoc.pdf

Rough-Wall Turbulent Boundary Layers

Background Drying is an important method to preserve food products. Although many traditional drying technologies (hot air, freeze, microwave drying) have been applied successfully to various food products, each drying technique has its own advantages and disadvantages. Novel drying methods such as infrared drying, have become very popular. Scope and approach This study gives an overview on the application of infrared radiation in the drying of food products in the last decade. The effects of main parameters (infrared power, intensity, distance, wavelength and drying temperature) and the introduction of infrared radiation on drying kinetics and food quality were discussed. Inconsistencies were pointed out and analyzed in detail. Key findings and conclusions: Drying kinetics was improved by introducing infrared radiation and increased with increasing infrared power, intensity, drying temperature and decreasing infrared distance. However, a very high infrared power, intensity, drying temperature and a very low infrared distance should be avoided as the food products will be overheated. The effects of infrared parameters on food quality were unpredictable. The energy consumption under infrared radiation was also variable. When the reduction of drying time was considerable, the energy consumption decreased. When the reduction was insufficient, the energy consumption increased. The application of infrared radiation will also affect the food quality. Generally, the infrared radiation can decrease the water activity, reduce the total color change and improve the nutrient retention.

Application of infrared radiation in the drying of food products

Effect of the dimple location and rotating number on the heat transfer and flow structure in a pin finned channel

Heat transfer in the trailing region of gas turbines – A state-of-the-art review

Flow structure and heat transfer characteristics in a 90-deg turned pin fined duct with different dimple/protrusion depths

The purpose of this paper is to investigate the optimal geometry parameters in a dimple/protrusion-pin finned channel with high thermal performance.,The BSL turbulence model is used to calculate the flow structure and heat transfer in a dimple/protrusion-pin finned channel. The optimization algorithm is set as Non-dominated Sorting Genetic Algorithm II (NSGA-II). The high Nusselt number and low friction factor are chosen as the optimization objectives. The pin fin diameter, dimple/protrusion diameter, dimple/protrusion location and dimple/protrusion depth are applied as the optimization variables. An in-house code is used to generate the geometry model and mesh. The commercial software Isight is used to perform the optimization process.,The results show that the Nusselt number and friction factor are sensitive to the geometry parameters. In a pin finned channel with a dimple, the Nusselt number is high at the rear part of the dimple, while it is low at the upstream of the dimple. A high dissipative function is found near the pin fin. In the protrusion channel, the Nusselt number is high at the leading edge of the protrusion. In addition, the protrusion induces a high pressure drop compared to the dimpled channel.,The originality of this paper is to optimize the geometry parameters in a pin finned channel with dimple/protrusion. This is good application for the heat transfer enhancement at the trailing side for the gas turbine.

Lei Luo

Papers

Application of infrared radiation in the drying of food products

Effect of the dimple location and rotating number on the heat transfer and flow structure in a pin finned channel

Heat transfer in the trailing region of gas turbines – A state-of-the-art review

Flow structure and heat transfer characteristics in a 90-deg turned pin fined duct with different dimple/protrusion depths

Multi-objective optimization of the dimple/protrusion channel with pin fins for heat transfer enhancement