Guenter Zwarg, Consulting Engineer for Ventilation of Motors and Generators

Günter Zwarg

his patents     his papers

Mr. Gunter Zwarg was born in 1943 in Berlin, Germany. After an apprenticeship as an electro-machine builder, he studied at the Beuth Engineering Faculty in Berlin, where he finished with a Master in Electro-technics in 1965.
Following his studies, he worked at Siemens Large Drives in Berlin untill 2006. Since then he has been working as a freelance consulting engineer, mainly on the ventilation and cooling of large hydro generators at Voith.

Cooling of Siemens large drives and hydro generators

After some years working at the Dynamowerk, he was promoted as Lead Engineer for the cooling of large drives and hydro-generators.
Gunter has developed and designed the cooling and ventilation of DC Motors, asynchronous motors (slip ring motors and squirrel cage rotor), synchronous motors (pole-salient and full poles) as well as hydro generators and wind turbine generators.
He has designed the cooling of the following machines: Itaipu, PA4, Inga, Emborcacao, Darthmouth, Leitzach, Scanwind (3MW), Wassen, Keban, Herdecke, Machicura, Colbun, Taquarucu, Tiefencastel, Natpha Jhakri, Gordon, Kinda, Marsyangdi, Tevla …
Mr. Zwarg was responsible for worldwide customer services, commissioning support, turn-Over Measurements (ventilation, heating and calometrical loss measurements), qualified measurements in the field as well as damage analysis for the following machines: Bhira, Ilha Soltaira, Cartagena, Guangzhou, Häusern, Scanwind (3MW), Vianden, Dravograd, Inga, Jin Wei Zhou, Froystul….  He was usually in the field, in order to perform ventilation measurements and specially qualified measurements.

Design of axial fans, radial fans and heat exchangers

He has developed programs for the design of air-to-air heat exchangers and air-to-water heat exchangers. He has supervised CFD flow and thermal calculations as well as the development of heat source networks.

Calculation methods and their validation

Gunter has extensive experience in the development and use of calculation methods for the cooling of rotating electrical machines. He has recently developed a user-friendly flow network for the cooling of hydro generators, this tool calculates in a physically correct way the pressure drops and the flows for any imaginable ventilation system. The main method was finalized in 2000, the program is still in development for special machines. As part of this tool development, he developed a hydro- generator model reduced to the ratio 1:7.33 for the measurement of flow coefficients and heat transfer coefficients. The part models are used for the determination of the pressure loss coefficients due to the friction and due to geometry changes, these are needed for the Bernoulli equation. This tool could be expanded for hydro generators, wind generators, turbo generators, turbo motors and ring motors.

Development of advanced innovative technology

  • Cooling with synthetic mediums
  • Development of fan blades for composite axial fans with a 260 m/s circumferential speed up to serial production, in co-operation with a Brazilian partner (finished in 2006)
  • Development and dimensioning of cooling systems with liquid medium for the retrofit of high voltage motors (finished in 2005)
  • Report on the consequences of transonic flow speeds on the ventilation, heating and efficiency for extremely fast rotating motors (2004 - 2006)
  • Dimensioning of the cooling systems for 5.5 MW and 13500 rpm asynchronous motors on customer request (2005 - 2006)

He has worked on several projects for the cooling of salient pole motors with the e-cooling CFD engineering office.