## 1 Introduction
Setting guide vanes in the radial inlet is beneficial for improving the flow field. However, the guide vane wake generates one more aerodynamic load on the impeller due to the rotor-stator interaction (RSI) [22]. Furthermore, hydrogen as the working fluid can easily raise the hydrogen embrittlement in the compressor. Therefore, the RSI and hydrogen embrittlement threaten hydrogen compressor safety. The trailing edge blowing (TEB) proposed by [PERSON] and [PERSON] [23] is an active control method to reduce the effect of wake and RSI. According to the wake characteristics, the wakes can divide into four categories: the pure wake, the weak wake, the momentumless wake, and the jet. [PERSON] et al. [24] measured the mean velocity profiles of the wake and indicated that the momentumless wake made the inlet flow of the rotor more uniform and improved the inlet flow angle of the rotor. By adding an extra 2% flow rate for TEB, [PERSON] et al. [25] decreased about 43% of the amplitude at the blade passing frequency in the Francis turbine. Based on the centrifugal compressor with TEB on the guide vanes, [PERSON] et al. [26] analyzed the flow field and aerodynamic load on the impeller. When obtaining the momentumless wake, the aerodynamic loads on the impeller had reduced significantly. Combined with the TEB method, [PERSON] et al. [27] investigated the effect of the radial inlet guide vane. The results showed that the TEB reduced the wake intensity and decreased the aerodynamic load, which ensured a smooth operation and provided a long lifetime for the compressor. Moreover, the passive control method was suitable for reducing the total pressure loss and decreasing the wake intensity in turbomachinery. [PERSON] et al. [28] set the slot in the rotor for the axial fan and led the fluid flow from the root to the tip by centrifugal force. This performance improved the flow field near the tip region, decreased the boundary layer separation, and increased the fan efficiency. Based on a cavity for flow recirculation, [PERSON] et al. [29] adopted the ported shroud on the centrifugal compressor to avoid blade passage blocking in near-surge conditions. [PERSON] et al. (2019) added a two-slot configuration in the inlet guide vane of the compressor, and the results showed that the slot changed the wake distribution under different operation conditions ([PERSON] et al., 2019). Under winter conditions, i.e., the angle of 38.6\({}^{\circ}\), the slot produced a nearly 13% reduction of the amplitude of the impeller passing frequency at the leading edge. As the TEB method needs extra power from the outside of the compressor, this study adopted a passive control method, which employs the self-induced slot (SIS) on the guide vane. The hydrogen compressor with radial inlet was engaged in this paper to evaluate the effects of the SIS method on compressor performance and aerodynamic load on the impeller. Meanwhile, the TEB method was used for comparison in this study. Through the analysis using numerical simulation, the effects of the SIS method on the compressor performance, flow field in the radial inlet, and the aerodynamic load on the impeller were investigated. The organization of this paper is as follows. The second section describes the hydrogen compressor and the computational consideration, which includes the scheme of TEB and SIS methods. The aerodynamic load and the flow field in TEB and SIS models are analyzed in the third section compared with the UGV model. Lastly, the fourth section provides some conclusions.