<p>The geometry of radial turbine volutes is asymmetric, which results in circumferentially non-uniform airflow, especially in the vicinity of the tongue, where a region with significant abrupt pressure changes exists. In a vaneless housing turbine, blades are subjected to aerodynamic excitation forces induced by such non-uniform pressure distribution, which can lead to High Cycle Fatigue (HCF) of the blades. In this paper, a blade vibration suppression method is proposed, in which a groove is added on the turbine housing shroud close to the rotor trailing edge (TE). This method is applied to an industrial turbocharger turbine for heavy-duty truck applications, and the vibration responses of the rotor exducer (Mode 1) and rotor inducer (Mode 2) are both investigated. A one-way fluid-structure interaction (FSI) numerical approach is adopted in the analysis. The numerical results show that a single groove location with periodic arrangement on the circumference of the housing shroud effectively reduces blade vibration stresses, and more than 80% reduction of the maximum vibratory stress can be achieved under the engine order 3 (EO3) resonance condition for Mode 1. A design of experiments (DOE) method is employed to analyse the effect of groove geometry on vibration suppression. The results indicate that both groove width and length play an important role in determining the excitation force magnitude, and these two parameters exhibit a positive interactive effect that mutually enhances the vibration suppression effect.</p>