"水斗式水轮机" can be translated into English as "Pelton turbine" or "bucket-type water turbine".
"Pelton turbine" is the more commonly used and technical term in the field of hydropower engineering, named after its inventor Lester Allan Pelton.
"Bucket-type water turbine" is a more descriptive translation that directly refers to the characteristic of the turbine having buckets (or cups) to capture the water's energy.
In most professional and technical contexts, "Pelton turbine" would be the preferred choice.