  Dielectric Barrier Discharge (DBD) plasma actuators with an asymmetric,
straight edge electrode configuration generate a wall-bounded jet without
moving parts. Mechanistic description of the interaction between the Coulombic
forces and fluid motion as a function of DBD parameters remains unclear. This
paper presents an experimental investigation of DBD actuator, including
electrical current associated with microdischarges, plasma volume, and the wall
jet momentum over a range of AC frequencies (0.5 - 2 kHz) and peak-to-peak
voltages up to 19.5 kV. Discharge current is measured with a high temporal
resolution, and plasma volume is characterized optically, and the momentum
induced by the DBD wall jet is computed based on the axial velocities measured
downstream of the actuator using a custom-built pitot tube. Discharge current
analysis demonstrated asymmetry between the positive and negative semi-cycle;
both currents yielded a power-law relationship with empirical fitting
coefficients. Plasma length varies linearly and volume quadratically with
voltage. Although plasma length reached an asymptotic value at a higher
frequency, the plasma volume grows due to the increasing height of the
ionization region. In a simple 2D configuration, the DBD wall jet momentum
shows near-linear dependency with discharge current in the range of voltages
and frequencies considered in this work. The presented empirical model
characterizes the DBD wall jet momentum and the discharge current based only on
the AC inputs. With the estimation of plasma volume, the model can be applied
for determining more realistic boundary conditions in numerical simulations.
