# Numerical Solution — Lesson 6

### Solution Methods

In the Outline window, select Solution Methods to open the Solution Methods window. Under Spatial Discretization, change the option under Momentum from First Order Upwind to Second Order Upwind. Under Energy, also change the option to Second Order Upwind.

### Monitors

In the Outline window, click Monitors to open the Monitors window. In the Monitors window, select Residuals - Print,Plot and press Edit.... This will open the Residual Monitors window. We want to change the convergence criteria for our solution. Under Equation and to the right of Continuity, change the Absolute Criteria to 1e-6. Repeat for x-velocityy-velocity, and energy, then press OK.

### Reference Values

In the Outline window, select Reference Values. Under Compute From, select Inlet. Ensure that the values displayed are the values we specified.

### Solution Initialization

In the Outline window, select Solution Initialization. We need to make an "Initial Guess" to the solution so Fluent can iterate to find the final solution. In the Solution Initialization window, select Standard Initialization then under Compute from, select Inlet from the drop-down box. Check to see that the values that are generated match our input values, then press Initialize.

### Data File Quantities

After we have initialized the solution, we can select additional quantities to be transferred over to CFD-Post. These quantities are not selected by default and so we must select them ourselves. Go to File>Data File Quantities. Under Additional Quantities, find and select Skin Friction Coefficient and click OK.

### Run Calculation

In the Outline window, select Run Calculation. Change the Number of Iterations to 1000. Double click Calculate to run the calculation. After the iterations have converged, save the project, and you may close the solver.