Preliminary Design and Analysis of a Hydrostatic Force Excited Governor

Mechanical speed governors traditionally rely on centrifugal masses to convert rotational speed into a control displacement. These systems, however, are susceptible to frictional wear and sensitivity to parameter variations. To address these limitations, this paper investigates a hydrostatic-force–based governor in which the axial displacement of a sleeve is generated by the pressure field of a fluid undergoing rigid-body rotation inside a cylindrical container. The analysis begins by establishing the stationary and rotating equilibrium of the sleeve using inviscid-flow assumptions and the classical rigid-body pressure distribution. These relations yield closed-form expressions for the upward force on the sleeve and define the geometric constraints required to achieve a prescribed displacement at a given angular velocity. A preliminary design methodology is presented based on these analytical expressions. Transient fluid behavior during angular acceleration is then examined using time-dependent simulations. The results show that the pressure field requires several seconds to converge to rigid-body form, producing a measurable delay between shaft acceleration and sleeve response. The weak influence of container diameter on delay simplifies design optimization. Overall, the proposed concept provides predictable steady-state mapping and inherently damped transient behavior, offering a promising alternative to traditional mechanical or hydraulic governors.

Keywords:

hydrostatic governor , rigid-body rotation , transient fluid dynamics , centrifugal governor alternatives , fluid–structure interaction