Rudolf Arnold Erren (15 August 1899 – death date unknown) was a German engineer and inventor who did important work on the use of hydrogen fuels in the early 20th century.
He had several patents, developed the Erren engine,[1] and his work was "apparently the earliest reported use of hydrogen-engine supercharging of any kind.
"[2] One of Germany's World War II U-boats supposedly had a hydrogen engine designed by Erren.
"[4] Erren was interned in Canada by the British during World War II[5] and repatriated 28 October 1945.
[8][9][4] The Rudolf Erren Award of the International Association of Hydrogen Energy (IAHE) is named in his honor.