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A dimensionless number is a quantity that is normalized as to negate the differences in properties from one substance to another. They are used to enable scientists and engineers to make direct comparisons between dissimilar substances. An example, commonly used in both Fluid Dynamics and Heat Transfer is the Reynolds number expressed as Re = density*velocity*L/mu or Re = velocity*L/nu, where L is the characteristic length, mu is the dynamic viscosity, and nu is the kinematic viscosity. Using the Reynolds number, comparisons between two dissimilar substances (e.g. Glycerine, Water, Alcohol, and Blood) can be made. The nussalt number in heat transfer is a dimenssionaless number and it is the ratio of conductive to convective heat transefer across a boundary.
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What is ntu in thermodynamics?
NTU is nothing but Number of Transfer Units. It is one of the method used to find the heat transfer of hot and cold body it is applicable to both parallel and counter flow.============The NTU Method is used to calculate the rate of heat transfer in heat exchangers when there is insufficient information to calculate the Log-Mean Temperature Difference (LMTD). If fluid inlet and outlet temperatures are specified or can be determined by simple energy balance, the LMTD method should be used; but when these temperatures are not available The NTU or The Effectiveness method is used. It is based off of the maximum possible heat exchange in an infinitely long heat exchanger. From this, different heat exchangers can be compared and estimates of actual heat exchange calculated based on the NTU effectiveness.
What materials transfer heat the best?
Materials that conduct heat well, such as metals like copper and aluminum, transfer heat the best. These materials have a high thermal conductivity, allowing them to efficiently transfer heat from one point to another. Insulating materials, on the other hand, do not transfer heat well and are used to reduce heat transfer.
What heat transfer is being used when a heat lamp is heating a box?
The heat transfer being used in this scenario is radiation. The heat lamp emits infrared radiation that is absorbed by the box, causing its temperature to increase.
What type of heat transfer is used in curtains?
Conduction is the main type of heat transfer used in curtains. The material of the curtain absorbs and conducts heat, which helps to regulate the temperature in the room by either retaining or blocking heat.
What is the ambient temperature formula used to calculate the overall heat transfer in a given environment?
The formula used to calculate overall heat transfer in a given environment is Q U A T, where Q is the heat transfer rate, U is the overall heat transfer coefficient, A is the surface area, and T is the temperature difference between the object and the environment.
What is phase change number?
The phase change number is a dimensionless number used in heat transfer that represents the ratio of sensible heat transfer to latent heat transfer during a phase change process. It helps quantify the relative importance of sensible and latent heat transfer mechanisms.
What is ntu in thermodynamics?
NTU is nothing but Number of Transfer Units. It is one of the method used to find the heat transfer of hot and cold body it is applicable to both parallel and counter flow.============The NTU Method is used to calculate the rate of heat transfer in heat exchangers when there is insufficient information to calculate the Log-Mean Temperature Difference (LMTD). If fluid inlet and outlet temperatures are specified or can be determined by simple energy balance, the LMTD method should be used; but when these temperatures are not available The NTU or The Effectiveness method is used. It is based off of the maximum possible heat exchange in an infinitely long heat exchanger. From this, different heat exchangers can be compared and estimates of actual heat exchange calculated based on the NTU effectiveness.
What is heat conductor used for?
Its used to transfer heat into electrical signal
What do conduction and convection have in common?
They're both modes of heat transfer via material media.
What is the formula for Nu?
The Nusselt number (Nu) is dimensionless and represents the ratio of convective to conductive heat transfer. It is commonly calculated as Nu = hL/k, where h is the convective heat transfer coefficient, L is a characteristic length, and k is the thermal conductivity of the fluid. Additional correlations and equations may be used depending on the specific flow conditions and geometry.
What is a radiator used for?
To transfer heat.
Define view factor in heat transfer?
The view factor, also known as the configuration factor or shape factor, is a dimensionless quantity used in heat transfer to describe the proportion of radiation leaving one surface that directly reaches another surface. It is essential in calculating radiation exchange between surfaces in a geometrical arrangement. The view factor depends on the geometry and orientation of the surfaces involved and is typically used in the context of radiative heat transfer calculations. In a closed system, the sum of view factors from one surface to all other surfaces equals one.
What is the answer to the analogy fiberglass is to insulation as conduction is to what?
The answer is "heat transfer." Fiberglass is commonly used as insulation to reduce heat transfer, while conduction is a form of heat transfer where heat is transferred through a material.
What materials transfer heat the best?
Materials that conduct heat well, such as metals like copper and aluminum, transfer heat the best. These materials have a high thermal conductivity, allowing them to efficiently transfer heat from one point to another. Insulating materials, on the other hand, do not transfer heat well and are used to reduce heat transfer.
What term is used for heat transfer because of te movement of a gas?
Convection is the transfer of heat through the movement of a fluid, whether liquid or gas.
A dimensionless number which is a ratio of kinematics viscosity to thermal diffusivity is known as?
The Prandtl Number is a dimensionless number approximating the ratio of momentum diffusivity (kinematic viscosity) and thermal diffusivity and can be expressed asPr = v / αThe Prandtl number can alternatively be expressed asPr = μ cp / kThe Prandtl Number is often used in heat transfer and free and forced convection calculations. where:ν : kinematic viscosity, ν = μ / ρ, (SI units : m2/s)α : thermal diffusivity, α = k / (ρcp), (SI units : m2/s)μ : dynamic viscosity, (SI units : Pa s)k: thermal conductivity, (SI units : W/(m K) )cp : specific heat, (SI units : J/(kg K) )ρ : density, (SI units : kg/m3 ).answered by : eng_moom
What heat transfer is being used when a heat lamp is heating a box?
The heat transfer being used in this scenario is radiation. The heat lamp emits infrared radiation that is absorbed by the box, causing its temperature to increase.
