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Half Time presentation of studies and research of the sustainable Green Revolution Energy Converter (GREC) motor concept, that promises crucial climate-positive adjustable clean energy production.


The severe impacts of green house gas emissions on the global warming is today a fact. The emissions can be coupled to several different sectors where heat and electricity production were the sectors with the highest increase of CO2 emissions in 2021. The complexity of this turns out to be greater than imagined since no bigger improvements has happened since the Paris Agreement was signed by 196 UN countries in 2015 and here we are in 2022 with COP27. Still new technological solutions to inverstigate and luckily there are two groups at Linköping University in Sweden that thrive on the challenge of a transition to a world not based on fossil fuels. Investigating a new technology aiming to be applied both in the electricity production sector and the transport sector.

The nilsinside GREC project at Linköping University Sweden
Standing from the left: Johan Hagströmmer, Vendela Stenholm, Oscar Torsteinsrud, Maja Abrahamsson Bolstad, Emma Andersson, Matilda Eriksson
Below from the lef: Mattias Reijm, (on photo) Emma Gustafsson, Wilma Fager

Joint Presentation

Members of the two GREC groups started with a joint introduction of their half time presentation overview.
This included a brief presentation the Revolving Work Generating Volume technology, its scalability, some application examples even with small temperature gradients.
The nilsinside projects at Linköping University Sweden
Putting it all together at Linkoping University Sweden, the steps includes:
• The 2022 spring project (done) - Theoretical proof of concept with
• Calculations in MATLAB
• Material analysis
• Thermal simulations.

Autumn project groups 2022 (half-time)
• Internal heat transfer reseach
• External heat transfer research

Spring project 2023 (planned)
• Build a new Lab model, v3

IHT group

The GREC Internal Heat Transfer Group (IHT: to the upper left in the picture above, Johan Hagströmmer, Vendela Stenholm, Oscar Torsteinsrud and sitting Mattias Reijm) continued the presentation explaining their exiting challenges and their findings so far.
The Work Generating Volume
The IHT group Objective and specific aims:

• Study the characteristics of the airflow in the WGV depending on the rotor speed, rotor radius and thickness of WGV.
• Study the effects on heat transfer and temperatures in the WGV, due to the earlier mentioned fluid flows.
• Study the effects on air flow and heat transfer by adding laminar breakers.
• Study the effects on air flow and heat transfer depending on the shape of the rotor. Should there be one slit as a quarter of the disc, for the WGV, or two symmetrically placed slits that each take up an eight of the disc area?
• The subsequent pressure changes in the motor will be studied, also in COMSOL, in order to evaluate the potential work.

EHT group

The GREC External Heat Transfer group (EHT: to the right in the picture above, Maja Abrahamsson Bolstad, Emma Andersson Matilda Eriksson and below Emma Gustafsson and sitting Wilma Fager) followded with their presentation explaining their challenges interfacing external energy storages to the GREC Work Generating Volume.They are doing a thermal investigation of one conductive fin and heat block in the GREC heat engine
• Method None-Pipe Model
Conductive Fin External Heat Transfer
• Method Pipe Model "sling" and "linked U"
COP27 ANSYS setup Conductive Fin
Setting it all up in ANSYS:
nilsinside ANSYS setup Conductive Fin

COP27 ANSYS setup Conductive Fin

The Technology

In thermodynamic terms the GREC is a closed system with a moving boundary where the GREC converts heat energy to kinetic energy. The GREC heats up and cools down its internal large sliced “Work Generating Volume” (WGV) efficiently, fast and repetitively, resulting in internal pressure changes. These internal pressure changes are used by its moving boundary to generate kinetic energy. You may think of the GREC as a revolving Carnot heat engine controlled by computer logic. Please find the theoretical presentation of the GREC on this link:
GREC Theory Presentation

You may download the Sustainable Project PART2 document as a .pdf file by clicking this link:
Sustainable Revolution PART2 at Linköpings Universitet

The GREC is a new technological solution to tackle climate change and luckily there are two groups at Linköping University that thrive on the challenge of a transition to fossil free energy systems. The GREC is a climate positive project that needs several research projects over time...
Please feel free to call or email:

Contact information at nilsinside AB
Nils Karlberg, tel +33 608 53 15 93, theory & technical questions
Sophia Karlberg , strategy & admin questions

The GREC Project