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A new implicit monotonized scheme of second-order accuracy and Newton's method for solving the grid equations approximated the Navier-Stokes equations were developed to simulate the two-dimensional hypersonic viscous flow about a plate located in the wakes of a cylinder. The strong influence of the geometrical factor of interference between a plate and a cylinder (characterized by the normalized distance between the bodies) on skin friction and heat flux along the plane and cylinder surfaces have been found The changes of temperature, pressure and velocity fields in the wake behind the cylinder have been analyzed. Nomenclature C f = local skin friction coefficient c p = specific heat at constant pressure c v = specific heat at constant volume E = flux-vector in curvilinear coordinate system, Eqs.(l),(2) e = total energy per unit volume, pfcj'+tf + vO/2) G = flux-vector in curvilinear coordinate system, Eqs.(l),(2) H = total enthalpy per unit volume, c p T + (u 3 + v 7)/! h = node size J = Jacobian of the coordinates transformation

Methods and relevant software were developed to study frequency dispersion parameters of wideband high‐frequency (HF) radio channels over propagation paths of different lengths: near vertical incidence skywave paths (up to 500 km) and long‐distance radio paths (from 1,000 up to 3,500 km). We developed a universal ionosonde (in terms of methods and signals) to do experimental research into HF radio wave propagation and dispersion using software‐defined radio technology and platform Universal Software Radio Peripheral N210. The multipurposeness of the ionosonde is manifested in the sounding methods used (oblique incidence and vertical incidence) as well as in the spread spectrum signals used (binary phase shift keying, frequency modulated continuous wave, and frequency modulated interrupted continuous wave). The characteristics of the megahertz‐bandwidth HF channels were studied. The dependences of the variation of the third‐order dispersion parameter on the time of day, the radio path length, and the channel carrier frequency were experimentally found.

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