## 1 Introduction  
The demand for lighter and more efficient aero engines has significantly grown during the last few years. To address these issues, modern compressors have been conceived with increasingly larger pressure ratios per stage. Natural consequences of these solutions are an aggressive blade loading and high flutter sensitivity, especially for long and slim blades. Fatigue phenomena, due to large vibratory loads, are severely enhanced [1, 2]. Blade design approaches aiming specifically to provide a reduction in vibratory loads and a delay of the flutter onset were proposed, e.g., in Refs. [3, 4]. In addition, the aerodynamic performance is significantly affected on such highly loaded blades. Indeed, larger pressure gradients over the blade suction surface may accelerate the stall onset, therefore degrading the overall compressor performance. Several active flow control solutions have been proposed to optimize the aerodynamic response of heavily loaded blades. [PERSON] et al. [5] investigated experimentally the effect of steady and pulsed blowing through side wall actuators on a linear compressor cascade. They showed that both steady and pulsed jets are effective in suppressing three-dimensional secondary flow phenomena occurring on critically loaded blades. [PERSON] et al. [6] employed a synthetic jet located on the side wall at the level of the blade leading edge. A positive effect of such actuation on the flow field and on the loss coefficient was found. Similarly, a beneficial effect of side wall blowing on flow separation was found in Ref. [7]. Besides blowing, blade morphing has been extensively studied as a means to enhance the aerodynamic response of heavily loaded compressor and turbine blades. [PERSON] et al. [8] employed piezo actuators to control the blade shape. The resulting deformed blade was found to affect the measured aerodynamic loads significantly. [PERSON] et al. [9] investigated different adaptive blade solutions with numerical computations and experimental tests. Specifically, they studied and compared four morphing solutions, i.e., blades with adjustable angle of attack, movable leading edge, Gurney flaps, and adaptive camber. [PERSON] et al. assessed experimentally [10] and numerically [11] the effect of shape memory alloys for blade shape adaptation on a heavy-duty automotive cooling axial fan. Large interest has been latterly addressed toward plasma actuation. The suitability of these actuators stems from their lightness and their almost negligible intrusiveness into the flow field. Additionally, the absence of mechanical parts avoids the risk of structural and operational failures, likely to occur under high centrifugal loads typical of aero engines. [PERSON] et al. [12] carried out a computational assessment of plasma actuators installed on a transonic axial compressor. The capability of suppressing spike stall inception was assessed by taking into account several locations and strengths of the plasma actuators. The work of [PERSON] et al. [13] deals with the experimental and numerical characterization of plasma actuators in a compressor cascade. It was shown that properly tuned plasma actuation allows for an effective reduction of pressure losses on highly loaded compressor blades. [PERSON] et al. [14] performed numerical and experimental assessments of plasma actuators to control corner stall separation on a heavily loaded blade cascade. In this work, realistic operation conditions were simulated. It was found that a combination of plasma actuators placed on the suction surface is a very effective means to control flow separation and in turn pressure losses. [PERSON] et al. [15] carried out numerical investigations of plasma actuators to control flow separation on a high-speed compressor cascade. The effects of both endwall and suction side plasma actuators were studied. The purpose of the present work is to assess numerically the effectiveness of plasma actuators for load alleviation on a compressor cascade.