Here is a compilation of essays on ‘Thermal Radiation’ for class 9, 10, 11 and 12. Find paragraphs, long and short essays on ‘Thermal Radiation’ especially written for school and college students. Essay on Thermal Radiation Essay Contents: Essay on the Meaning of Thermal Radiation Essay on the Salient Features and Characteristics of Radiation Essay on Absorptivity, Reflectivity and Transmissivity [...]
The following points highlight the five important laws of radiation. The laws are: 1. Wavelength Distribution of Black Body Radiation: Planck's Law 2. Total Emissive Power; Stefan-Boltzman Law 3. Wien's Displacement Law 4. Kirchoff's Law 5. Intensity of Radiation and Lambert's Cosine Law. 1. Wavelength Distribution of Black Body Radiation: Planck's Law: The energy emitted by a black surface varies [...]
In this article we will discuss about:- 1. Meaning of Convection 2. Laminar and Turbulent Flow of Fluid Affecting Convection 3. Newton-Rikhman Law 4. Dimensionless Group 5. Significance. Contents: Meaning of Convection Laminar and Turbulent Flow of Fluid Affecting Convection Newton-Rikhman Law: Convection Rate Equation Dimensionless Group for Convection Significance of Dimensionless Groups for Convection 1. Meaning of Convection: Thermal [...]
In many situations of practical importance, heat is generated internally at uniform rate within the conducting medium itself. Notable examples are: (i) Resistance heating in electrical appliances; essentially it is the conversion of electrical energy into thermal energy in the current carrying medium (ii) Energy generated in the fuel element of a nuclear reactor (iii) Liberation of energy due to [...]
Whether the boiling phenomenon corresponds to pool boiling or forced circulation boiling, there are three definite regimes of boiling associated with progressively increasing heat flux. These regimes have been identified in Fig. 12.8 which shows the relationship between heat flux (or film coefficient) and the temperature excess (ts – tsat); ts is the temperature of the hot surface and tsat [...]
In this article we will discuss about:- 1. Meaning of Condensation 2. Laminar Film Condensation on a Vertical Plate 3. Turbulent Film Condensation. Meaning of Condensation: Fluid in a gaseous or vapour phase changes to a liquid state with the liberation of heat from the vapour. When a vapour is in contact with a surface whose temperature ts is lower [...]
The heat transfer during a boiling process is governed by the convective heat transfer equation; Q = h A Δt Where, Q is the heat flow rate, h is the boiling film coefficient, A is the surface area and Δt is the temperature differential between the heating surface and the saturated liquid; Δt = ts – tsat. The boiling is [...]
Many types of heat exchangers have been developed to meet the widely varying applications. Based upon their, i. Operating principle ii. Arrangement of flow path iii. Design and certain constructional features, The heat exchangers can be classified into the following categories: 1. Nature of Heat Exchange Process: Based upon the nature of heat exchange process, the heat exchangers are classified [...]
In this article we will discuss about the performance of heat exchangers. The indicated parameters are: m = mass flow (kg/ s) c = specific heat (J/kg-deg) t = fluid temperature (deg C) Δt = temperature drop or rise of a fluid across the heat exchanger. Subscripts h and c designate the hot and cold fluids respectively; subscripts 1 and [...]
In this article we will discuss about the convective coefficient for film condensation on various tube arrangements. They are: 1. Convective Coefficient for Film Condensation on Vertical Tubes 2. Convective Coefficient for Film Condensation on Single Horizontal Tube 3. Convective Coefficient for Film Condensation on Banks of Horizontal Tubes 4. Convective Coefficient for Film Condensation inside Tubes. 1. Convective Coefficient [...]