California vs. US fuel price gap at 50.3% premium
StreetScooter brings on Tesla, Ford execs to focus on growth, internationalization

EERE announces lightweight turbocharger turbine wheel challenge

The US Department of Energy’s (DOE’s) Office of Energy Efficiency and Renewable Energy (EERE) announced a new manufacturing prize as part of the Manufacturing Innovator Challenge: the Lightweight Turbocharger Turbine Wheel Challenge.

C9765C54-0064-40F1-9FE4-E2E927EB1CF8

Photo credit: Oak Ridge National Laboratory


EERE has partnered with Freelancer.com since 2018 to hold crowdsourcing campaigns that attract innovative solutions to today’s manufacturing challenges and broad industry participation. The Manufacturing Innovator Challenge consists of individual challenges across multiple technologies to find ideas that will enhance manufacturing in the United States.

Many new engine concepts include a turbocharger to help increase thermal efficiency and increase power density (horsepower/liter displacement). The turbine and compressor wheels in the turbocharger rotate at speeds above 100,000 revolutions per minute. DOE seeks design concepts for a lightweight turbocharger turbine wheel that can meet or exceed the performance of an Inconel automotive component and have the ability to be scaled up to larger turbocharger applications.

Inconel is a family of austenitic nickel-chromium-based superalloys that are oxidation-corrosion-resistant and well suited for service in extreme environments subjected to pressure and heat.

When heated, Inconel forms a thick, stable, passivating oxide layer protecting the surface from further attack. Inconel’s high temperature strength is developed by solid solution strengthening or precipitation hardening, depending on the alloy.

To optimize the efficiency and transient response, the new design should take advantage of innovative manufacturing techniques (such as additive manufacturing) and new material concepts.

DOE will award one prize for a lightweight turbo turbine wheel concept, with a prize of approximately $7,000.

The contest submission will consist of a 5-page (maximum) report that must include:

  • Description of the technical approach

  • Materials envisioned (including mechanical properties)

  • Manufacturing approaches required (including finishing and/or joint technologies)

  • Comparison to existing component

  • Technical performance expectations and risks

  • Computer Aided Drafting (CAD) drawing or Mechanical Drawings of the concept

Evaluation criteria include:

  • Innovation (30/100): Degree to which proposed concept does not currently exist and/or meets an existing need

  • Impact (30/100): The amount of impact a technology solution could have

  • Feasibility (40/100): The technical feasibility of the proposed concept

Comments

Thomas Pedersen

How about those 3D-printed Ti-Al alloys used for the last two stages of modern jet engines. The have about the same properties as nickel-based alloys (tensile strength at those temperatures), but are employed exactly because of their weight savings, which are of course worth much more in a 777 than an automobile.

One a side note; transient response of turbo chargers should not be an issue in increasingly hybridized drive trains where even a 48V system can alleviate the 'problem' of turbo lag - either by direct electrical boost or by e-turbo as employed by Audi.

Peter_XX

Well, this is a competition for prize money, so we will see which solution wins. The ultimate solution might be ceramic but the question is if the mechanical properties are sufficient. Already as a young engineer a couple of decades ago, I held such turbine parts in my hands but they never got mature for production.

Re. transient response: Ask a driver and he/she will answer: more! We have all heard about the excellent transient response from Audi's e-booster on this site but I recently saw a magazine that compared to a conventional twin-turbo car from another german manufacturer and the latter was considered better regarding transient response.

gryf

Since Borg-Warner EFR Series Turbochargers already have TiAl turbine wheels and ceramic bearings (they are used in INDY Car Racing), we need to do better. They weigh half as much as Inconel, though cost twice as much (3D printing may lower cost a bit).
Let's get real exotic and use Inconel Microlattice turbines made by Direct Metal Laser Sintering (DMLS). We can still use the ceramic bearings.

gryf

You also may want to design the Microlattice Turbo like the Honeywell Garrett Dual Boost Turbocharger which uses an axial flow turbine with a dual-sided compressor wheel. They are used in the Porsche 919 EVO. A good read here.
Now all I need is a DMLS 3D printer.

gryf

I think Christian von Koenigsegg may have outdone everyone in his One:1 auto. It has a variable turbocharger with two housings in one which allows less back pressure at higher RPM. The turbine housing has a complex twisted shape that is fully 3D printed, with moving parts printed within the enclosed chamber, in Stainless Steel.

gryf

Finally, must mention ceramic matrix composites (CMC) that GE is using in the LEAP and T901 gas turbine engines. CMC weigh only 1/3 of Inconel turbine blades and are more durable than the older ceramic materials. However, they are probably too expensive for any auto application. Gurpreet Singh at Kansas State University has developed a Water-like Polymer Ceramic that may be low cost and simpler to manufacture (Reference: https://www.compositesworld.com/blog/post/the-next-generation-of-ceramic-matrix-composites).

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Working...
Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.

Working...

Post a comment

Your Information

(Name is required. Email address will not be displayed with the comment.)