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You can look at specific parts of the grid by choosing the items you wish to view under Surfaces (click to select and click again to deselect a specific boundary). Click Display again when you have selected your boundaries. Note what the surfaces farfield, wedge, etc. correspond to by selecting and plotting them in turn.

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In the Solver menu, select Density Based.

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Click OK.

Define > Models > Viscous

Select Inviscid under Model.

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Click OK. This means the solver will neglect the viscous terms in the governing equations.

Define > Models > Energy

In compressible flow, the energy equation is coupled to the continuity and momentum equations. So we need to solve the energy equation for our problem.

To turn on the energy equation, check the box next to Energy Equation and click OK.

Define > Materials

Make sure air is selected under Fluid Materials. Set Density to ideal-gas and make sure Cp is constant and equal to 1006.43 j/kg-k. Also make sure the Molecular Weight is constant and equal to 28.966 kg/kgmol. Selecting the ideal - gas option means that FLUENT will use the ideal-gas equation of state to relate density to the static pressure and temperature.

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Click Change/Create.

Define > Operating Conditions

To understand what the Operating PressureisPressure is, read through the short-and-sweet section 8.14.2 in the user's guide. We see that for all flows, FLUENT uses the gauge pressure internally in order to minimize round-off errors. Any time an absolute pressure is needed, as in the ideal gas law, it is generated by adding the operating pressure to the gauge pressure:

absolute pressure = gage gauge pressure + operating pressure

Round-off errors occur when pressure changes Δp in the flow are much smaller than the pressure values p. One then gets small differences of large numbers. For our supersonic flow, we'll get significant variation in the absolute pressure so that pressure changes Δp are comparable to pressure levels _ p. _ So we can work in terms of absolute pressure without being hassled by pesky round-off errors. To have FLUENT work in terms of the absolute pressure, set the Operating Pressure to 0.

Thus, in our case, there is no difference between the gauge and absolute pressures. Click OK.

Define > Boundary Conditions

Set farfield to pressure-far-field boundary type.

Then click Set.... Set the Gauge Pressure to 101325. Set the Mach Number to 3. Under X-Component of Flow Direction, put a value of 1 (i.e. the farfield flow isin the X direction).

Next, click on the Thermal Tab. Change the temperature to 300K. We are assuming ambient temperature.

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Click OK.

Set wedge to wall boundary type and symmetry to symmetry type.

Go to Step 5: Solve!