Polagye, BrianStrom, BenRoss, HannahForbush, DominicCavagnaro, Robert2019-09-092019-09-092019Polagye, B., Strom, B., Ross, H., Forbush, D. and Cavagnaro, R.J., 2019. Comparison of cross-flow turbine performance under torque-regulated and speed-regulated control. Journal of Renewable and Sustainable Energy, 11(4), p.044501.DOI: 10.1063/1.5087476http://hdl.handle.net/1773/44487Author's accepted proof, turbine experimental data, and code base to calculate performance coefficients and regenerate figures from experimental data.When experimentally evaluating the performance of a wind or water current turbine, one must impose a regulating torque on the turbine rotor by electrical or mechanical means. Some options limit this controlling torque to a purely resistive quantity, while servomotors and stepper motors allow torque to be applied in the direction of turbine rotation. Any control mode that results in net positive power for a turbine may be of interest for energy harvesting, and all of these are net “fluid-driven”. Here, we present experiments that characterize the power, torque, and force coefficients of a cross-flow turbine operated at a constant rotational speed or under a constant imposed control torque. Time- and phase-average performance coefficients are largely equivalent for the two strategies, though torque-regulated control is restricted to a narrower range of rotational speeds and the two strategies result in slightly different blade kinematics.en-USAttribution-NonCommercial-ShareAlike 3.0 United Stateshttp://creativecommons.org/licenses/by-nc-sa/3.0/us/cross-flow turbinecontrolhydrodynamicsArticle