Search results
Results from the WOW.Com Content Network
Drag coefficients in fluids with Reynolds number approximately 10 4 [1] [2] Shapes are depicted with the same projected frontal area. In fluid dynamics, the drag coefficient (commonly denoted as: , or ) is a dimensionless quantity that is used to quantify the drag or resistance of an object in a fluid environment, such as air or water.
If the fluid is a gas, certain properties of the gas influence the drag and those properties must also be taken into account. Those properties are conventionally considered to be the absolute temperature of the gas, and the ratio of its specific heats. These two properties determine the speed of sound in the gas at its given temperature.
the K-value is calculated from the data as: [8] = where: K is the horizontal saturated hydraulic conductivity (m/day) H is the depth of the water level in the hole relative to the water table in the soil (cm): H t = H at time t; H o = H at time t = 0
The Nusselt number may be obtained by a non-dimensional analysis of Fourier's law since it is equal to the dimensionless temperature gradient at the surface: =, where q is the heat transfer rate, k is the constant thermal conductivity and T the fluid temperature.
The three terms are used to define the state of a closed system of an incompressible, constant-density fluid. When the dynamic pressure is divided by the product of fluid density and acceleration due to gravity, g , the result is called velocity head , which is used in head equations like the one used for pressure head and hydraulic head .
For comparison purposes reference values are reported at an agreed temperature, usually 298 K (≈ 25 °C or 77 °F), although occasionally 20 °C (68 °F) is used. So-called "compensated" measurements are made at a convenient temperature but the value reported is a calculated value of the expected value of conductivity of the solution, as if ...
A Assuming an altitude of 194 metres above mean sea level (the worldwide median altitude of human habitation), an indoor temperature of 23 °C, a dewpoint of 9 °C (40.85% relative humidity), and 760 mmHg sea level–corrected barometric pressure (molar water vapor content = 1.16%). B Calculated values *Derived data by calculation.
A major use of the integrated equation is to estimate a new equilibrium constant at a new absolute temperature assuming a constant standard enthalpy change over the temperature range. To obtain the integrated equation, it is convenient to first rewrite the Van 't Hoff equation as [ 2 ]