A ventricular assist device (VAD) is a pump surgically connected to the heart and aorta in order to boost systemic blood flow in heart failure patients. The design of these devices has evolved over the past 30 years, with improvements and innovations enabled through the synergistic use of experimental research, clinical studies, and computational models. The application of computational fluid dynamics models has allowed the design of VADs to shift from large, bulky devices designed for patients with severe cardiac failure to a variety of smaller devices designed for a range of patients and cardiovascular conditions.