# Tools

Even though Paraview provides plenty of analysis tools, the **aerodynamicists ** often require some **specific tools** in order to perform a fast and comprehensive assessment. Epsilon tackles this issue by delivering multiple user-friendly dedicated tools.

### Extraction of body surface from CFD data

The surface of the body can be easily separated from the 3D domain data by using **Epsilon Near Field ** (This filter also computes the near-field forces and moments at the body surface).

### Wave drag extraction

**Epsilon Aero Data** computes the profile drag distribution for multiple aerodynamic analysis methods. In transonic cases, this profile drag mixes the viscous and wave drag components. Hence, **Epsilon Wave Drag** allows the user to separate both components from wake data.

_{ NOTE: Epsilon Aero Data also provides volume-based methods to compute wave drag directly at the shockwave volume. Hence, wave drag can be computed by multiple methods with the same level of accuracy.}

### Integration tool

**Epsilon Integration Tool** is a filter developed to perform multiple types of data integration, which are typically required during an aerodynamic analysis.

The simplest mode is the **single survey plane integral**, where the user defines a given survey plane position and then, the distribution of any parameter at the survey plane is integrated in order to provide the total survey plane quantity (like the total anergy or profile drag).

Another typical need while performing an aerodynamic analysis is to plot the distribution of a certain parameter along the chord or span of a body. For example, we would like to analyze the longitudinal evolution of the profile drag (and its components) all along the chord and wake of the airfoil (See image below). This kind of plot requires first performing a plane integral at several stations and then to plot the integrated values along the desired axis. This is achieved by an *automatic integration procedure* called **sweep survey plane**, which is provided by Epsilon Integration Tool.

The same integration technique can also be used to generate the spanwise distribution of any desired parameter.

### Mapping 3D data into a plane

Epsilon Integration Tool also allows generating a **3D to 2D mapping**. Basically, it takes the entire 3D volume flow field data and then it is integrated vertically all along a survey line. The result of this integral is stored onto a point of a plane. Then, this survey line is evaluated at each point of the mapping plane and the end result is that the plane will contain the surface distribution of the integrals along the normal direction to this plane, thereby generating a 3D to 2D integral mapping.

### Poisson solver

**Epsilon Poisson Solver** is a tool that allows solving the 2D Poisson equation . This tool is required by the **Maskell method** and the **wake-reduced exergy method** in order to calculate the **vortex drag**. This tool solves the Poisson equation starting from the axial vorticity field and gives the related stream function as well as the vortex drag density at the wake:

### Circulation and lift

**Epsilon Circulation Tool** is a fast and easy-to-use filter that allows computing circulation at multiple spanwise stations along the wing and to perform lifting line calculations (Lift, induced drag,...) from CFD data.

### Process 5HP calibration data

**Epsilon 5HP** allows analyzing a processing five-hole probe calibration data. It includes a fast graphical reduction method to compute probe velocity and pressures (Ps & Pt) from the hole pressures.

### Generate 5HP trayectories for wake survey

**Epsilon Grid Generator** is a wind tunnel testing dedicated tool that allows generating the five-hole probe path in order to perform wake surveys. You can generate any type of survey trayectory, from simple regular survey planes (to survey a large area) to wake-shaped trayectories from CFD data (to optimize the WTT run time).

### Real-time 5HP wake survey

**Epsilon Wake Survey** will allow you to visualize your five-hole probe measured data on the fly, during the WTT run. It reads your measurement file generated by your DAQ system and generates the 3D wake inside ParaView. Moreover, this wake data can be analyzed with the other Epsilon tools in real-time, for example, you can perform a wake-reduced aerodynamic analysis with the 5HP data.

### Analysis of PIV data

**Epsilon PIV ** is a tool suited for the pre-treatment of PIV data, thereby delivering a data set that is ready to be analyzed with Epsilon. It can do geometrical transformations, assembly of multiple PIV regions into a single mesh, PIV data cleanup and computing pressure from PIV. Moreover, the resulting pre-treated data from Epsilon PIV can then be analyzed with all the Epsilon tools, which allows you to perform a complete aerodynamic analysis from your PIV data.