The Fluid of Dynamics of Fire - Assignment Example

Classical mechanics of fluids. A) The laminar and turbulent flow. What is the transition and critical Reynolds number? Please enter at least two examples (3 points) Answer: The flow is in one of two main categories, or rules. The quantity of liquid friction, the amount of energy needed to obtain the scale depends on the type of flow. This is also an important consideration in some applications, the heat of the liquid. A laminar flow laminar flow is also used as a rationalization or viscous flow. (D.Lonel) The particles travel in irregular paths with no observable pattern layers and not definitive. Flow, i.e. in the tube, the channel flow in a wide and open channel flow. Heat transfer A) Describe what a dimension of physical parameters and include at least two examples of physical parameters and dimensions of (4 points). Answer: "In physics and thermodynamics, the heat (symbolized by Q) is the transfer of energy from one organism to another or from a difference in temperature. [1] In thermodynamics, the amount of TDS is used as a representative of the action (error) differential diagnosis of heat δQ is the absolute temperature of an object multiplied by the difference between the amounts of entropy of a system, measured at the boundary of the object.(S.Kakac) A concept of thermal energy, a generally defined as the energy of a body increases with the temperature. The total amount of energy through the heat transfer is conventionally abbreviated as V. The sign is that when a body releases heat into the surroundings, Q 0 (+). Heat-transfer, or heat flow per unit time, is indicated by the title:          \ Dot ((Q) = DQ \ over dt) \, \!. It is measured in watts. Heat flow is defined as the rate of heat transfer for eq section in units of watts per square meter, but slightly different notation conventions can be used.          () \ Frac (Q) (T) In 1865 he came to this relationship, symbolized by the entropy S, so that a closed, stationary system:          \ Delta S = \ frac (Q) (T) and, thus, reducing the amount of heat δQ (an incorrect differential diagnosis) is defined as TDS amount (an accurate differential diagnosis):          \ Delta Q = T dS \ In other words, the entropy S-function allows the quantification and measurement of heat flow through a thermodynamic limit. The energy between the two systems is the heat. Heat is a form of energy in the possession of a substance due to the vibration of the motion, the kinetic energy of molecules or atoms. The kinetic energy and heat are formally equal, but are not identical. Heat is the transfer of energy between substances different temperatures. Thermodynamics Domestic energy The heat is associated with the energy of the system, U and W with the system of the first law of thermodynamics:          \ Delta U = Q - W \ Type composition of the internal energy market (U) Sensitive part of energy, internal energy of a system as part of the kinetic energy (molecular translation, rotation and vibration, electronic spin and translation services and MRI) of the molecules. Latent energy of the internal market, energy associated with the phase of a system. Of chemical energy associated with the atomic bonds in a molecule. Nuclear power, the enormous amount of energy associated with the strong ties within the nucleus of the atom itself. Interaction energy of this form of energy in the system (e.g. heat transfer, mass transfer and work), but with the crossing of the border, because the profit or loss of a system in a process. The thermal energy is the sum of sensible and latent forms of energy. The heat transfer in an ideal gas at constant pressure increases the limit of energy and performs work (i.e. the ability to control the volume of gas to be larger or smaller), provided that the band is not limited. Back to the first equation and the work of separation in two kinds of "boundary" and "other" (for example, the tree of work performed by a compressor fan), provides the following information:          \ Delta U + W_ (border) = Q - W_ (other) \ Heat capacity Compressed for a simple system as an ideal gas in a piston, the changes in enthalpy and internal energy may be related to the heat capacity at constant pressure and volume, respectively. Limited to constant volume, heat, Q, for the change of temperature from an initial temperature T0, a final temperature (Eric W. Weisste) To is given by:          D = \ int_ (T_0) ^ (T_f) C_v \, dT = \ Delta U \, \! Remove the volume and the limitation of the system to expand or contract at constant pressure:          D = \ \ Delta U + \ int_ (V_0) ^ (P) V_f \, dV = \ \ Delta H = \ int_ (T_0) ^ (T_f) C_P \ DT \, \! The heat is an extensive quantity and, as such, depends on the number of molecules in the system. It may be presented as the product of the mass me of specific heat capacity, c_s \, \! by:          C_P = mc_s \, \! or depending on the number of moles and the molar heat capacity, c_n \, \! by:          C_P = nc_n \, \! In sufficiently liquid at low temperatures, quantum effects become important. An example is the behavior of bosons such as helium-4. The heat in the phase of a substance in this way is a "hidden" and thus the latent heat (from the Latin word that means "to lie hidden"). Latent heat is the heat per unit mass necessary to monitor the condition of a particular substance, or          L = \ frac (Q) (\ Delta m) \, \! E Q = \ int_ (M_0) (M) ^ L \ DM. Note that the pressure increases, the L rises slightly. Here, Mo is the amount of mass initially in the new phase, and M is the amount of mass, the new phase. Even L generally depends on the amount of mass that changes phase, so that the comparison is usually written as:          Q = LΔm. Sometimes L can be time-dependent if pressure and volume change with time, so the integral can be written as:          D = \ int L \ frac (DM) (dt) dt Heat transfer is the transfer of heat from one location to a warm radiator. If an object or a liquid at a temperature different from the environment or another object, transfer of thermal energy, also known as heat transfer or exchange of heat is made so that the body and the environment to reach the equilibrium heat. b) Describe the flow of heat radiation formula. (4 points) Answer: The thermal radiation is an important concept in thermodynamics, because it is partly due to the heat exchange between objects, as warmer bodies radiate more heat than its Colder. (Other factors are the conduction and convection.) The interaction of energy exchange is characterized by the following equation: \ Alpha + \ rho + \ tau = 1 \, Here, \ alpha \ is the spectral absorption factor, \ rho \, spectral reflectance and \ tau \, spectral transmittance. All these factors also depend on the wavelength \ lambda \,. The spectral absorption is equal to the rate of radiation \ epsilon \ this relationship is known as Kirchhoff's law of thermal radiation. An item is considered a black body and for all frequencies, namely the following formula:          \ Alpha = \ epsilon = 1 \, The formula below shows a man about 2 meters in the area, and about 307 Kelvin temperature, about 1000 watts of continuous output. However, if people in buildings, surrounded by surfaces at 296 K, they will get back about 900 watts from the wall, ceiling and other environment, so the net loss is about 100 watts. This heat transfer estimates are highly dependent on external variables, such as clothing (general downward thermal "circuit" of guidance, so that the total heat flow.) Only real "gray" of the systems (equivalent to the relative influence degree of water and non-directional transmission volume dependence in all positions into account.) can obtain reasonable estimates irradiated flow through the law of Stefan-Boltzmann. These calculations are important in solar energy, boiler and furnace design and computer graphics Raytracer. Power of thermal radiation from a black body per unit area, unit solid angle and unit frequency ν is given by the Planck law: This follows a mathematical formula to calculate the spectral distribution of energy in electro magnetic field Quantize that in full thermal equilibrium with the object that radiates. Integrating the equation ν on the performance of the law of Stefan-Boltzmann, including:          W = \ sigma \ CDOT A \ T ^ 4 CDOT In addition, the wavelength \ lambda \,,, for which the emission intensity is higher, is the law of Vienna as: \ lambda_ (max) = \ frac (b) (T) For areas that are not black bodies, should (in general frequency dependent) emissivity correction rate ε (υ). The formula for the force can be applied so that a correction of the temperature-dependent, that (a little 'confused) ε often:             W = \ epsilon (T) \ CDOT \ Sigma \ CDOT A \ T ^ 4 CDOT Constants Definitions of constants used in the above equations: h \, Planck constant 6626 0693 (11) × 10-34 J • s = 4135 667 43 (35) × 10-15 eV • S b \, the right-shift constant Wien 2897 7685 (51) × 10-3 m • K k_B \, Boltzmann constant 1380 6505 (24) × 10-23 J • K-1 = 8617 343 (15) × 10-5 eV K-1 • \ Sigma \ constant of Stefan-Boltzmann 5670 400 (40) × 10-8 W m-2 • • K-4 c \ speed of light 299792458 m • s-1 Variables The definitions of variables, with values of the sample: T \, the average temperature on Earth = 288 K A \, Cuba Area = 2ab + 2bc + 2AC; Acylinder = 2π • R (h + r); ASPHER 3rd Fluid dynamics of combustion technology A) Explain what the normal laminar flame speed. (4 points) The fundamental axioms of fluid dynamics are the laws of conservation, including conservation of mass, conservation of linear time (also known as Newton's second law of motion), and conservation of energy (also known as the first law of thermodynamics). These are based on classical mechanics and are modified in quantum mechanics and general relativity. You can use the transport theorem of Reynolds. The equations can be simplified in a number of opportunities that they are easier to solve. Some of them allow appropriate fluid dynamics problems are solved in closed form. In addition to mass, energy and momentum equations, a thermodynamic equation of state pressure as a function of other thermodynamic variables of the fluid needed to tackle the problem completely. An example would be the perfect gas equation:          p = \ frac (\ rho R_u T) (M) where p is the pressure, ρ is the density, Ru is the gas constant, M the molar mass and T is the temperature. b) an explanation of the number of Lewis Fry Richardson after Richardson (1881 to 1953). It is a dimensionless number which expresses the ratio between the potential of kinetic energy          Ri = (gh \ over u ^ 2) where g is the acceleration due to gravity, the vertical length of hauls representative and representatives of the speed. The treatment of differences in density are small (the Boussinesq approximation), it is usual, reducing the gravity g 'and its parameter is the number of Richardson densimetric          Ri = (g 'h \ U ^ 2) frequently used in the testing of ocean currents and weather. If Richardson is much less than unity, buoyancy is in the river. If there is a lot more unity, buoyancy dominated (in the sense that it is not enough kinetic energy to mix the liquids). When the Richardson number is unity, then the flow is expected for the energy flow due to the potential energy in the system initially. In aviation, the Richardson is a rough measure of expected turbulence. A result below indicates a higher degree of turbulence. Values range from 0.1 to 10 are typical, with values of unity, indicating significant turbulence. mathit (RI) = \ frac (g \ beta (T_ \ hot (lyrics) - T_ \ ref (Text)) L ^ 2) (v) where g is the acceleration due to gravity, β is the coefficient of thermal expansion, Thot is the hot wall temperature, TREF is the reference temperature, L is the characteristic length and V is the characteristic speed. The number of Richardson may also be achieved by a combination of Grashof number and Reynolds number,          \ Mathit (RI) = \ frac (G) Re ^ (2). Normally, the natural convection is negligible when Ri 10, and is not negligible, since 0.1 Read More

Back to the first equation and the work of separation in two kinds of "boundary" and "other" (for example, the tree of work performed by a compressor fan), provides the following information:          \ Delta U + W_ (border) = Q - W_ (other) \ Heat capacity Compressed for a simple system as an ideal gas in a piston, the changes in enthalpy and internal energy may be related to the heat capacity at constant pressure and volume, respectively. Limited to constant volume, heat, Q, for the change of temperature from an initial temperature T0, a final temperature (Eric W. Weisste) To is given by:          D = \ int_ (T_0) ^ (T_f) C_v \, dT = \ Delta U \, \!

Remove the volume and the limitation of the system to expand or contract at constant pressure:          D = \ \ Delta U + \ int_ (V_0) ^ (P) V_f \, dV = \ \ Delta H = \ int_ (T_0) ^ (T_f) C_P \ DT \, \! The heat is an extensive quantity and, as such, depends on the number of molecules in the system. It may be presented as the product of the mass me of specific heat capacity, c_s \, \! by:          C_P = mc_s \, \! or depending on the number of moles and the molar heat capacity, c_n \, \!

by:          C_P = nc_n \, \! In sufficiently liquid at low temperatures, quantum effects become important. An example is the behavior of bosons such as helium-4. The heat in the phase of a substance in this way is a "hidden" and thus the latent heat (from the Latin word that means "to lie hidden"). Latent heat is the heat per unit mass necessary to monitor the condition of a particular substance, or          L = \ frac (Q) (\ Delta m) \, \! E Q = \ int_ (M_0) (M) ^ L \ DM.

Note that the pressure increases, the L rises slightly. Here, Mo is the amount of mass initially in the new phase, and M is the amount of mass, the new phase. Even L generally depends on the amount of mass that changes phase, so that the comparison is usually written as:          Q = LΔm. Sometimes L can be time-dependent if pressure and volume change with time, so the integral can be written as:          D = \ int L \ frac (DM) (dt) dt Heat transfer is the transfer of heat from one location to a warm radiator.

If an object or a liquid at a temperature different from the environment or another object, transfer of thermal energy, also known as heat transfer or exchange of heat is made so that the body and the environment to reach the equilibrium heat. b) Describe the flow of heat radiation formula. (4 points) Answer: The thermal radiation is an important concept in thermodynamics, because it is partly due to the heat exchange between objects, as warmer bodies radiate more heat than its Colder. (Other factors are the conduction and convection.) The interaction of energy exchange is characterized by the following equation: \ Alpha + \ rho + \ tau = 1 \, Here, \ alpha \ is the spectral absorption factor, \ rho \, spectral reflectance and \ tau \, spectral transmittance.

All these factors also depend on the wavelength \ lambda \,. The spectral absorption is equal to the rate of radiation \ epsilon \ this relationship is known as Kirchhoff's law of thermal radiation. An item is considered a black body and for all frequencies, namely the following formula:          \ Alpha = \ epsilon = 1 \, The formula below shows a man about 2 meters in the area, and about 307 Kelvin temperature, about 1000 watts of continuous output. However, if people in buildings, surrounded by surfaces at 296 K, they will get back about 900 watts from the wall, ceiling and other environment, so the net loss is about 100 watts.

This heat transfer estimates are highly dependent on external variables, such as clothing (general downward thermal "circuit" of guidance, so that the total heat flow.) Only real "gray" of the systems (equivalent to the relative influence degree of water and non-directional transmission volume dependence in all positions into account.

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