is link wheel is effective for keywords ranking now a days ?

No link wheel now consider as black hat seo techniques. So Google ignore link wheel methods of link buildings.

Link wheel is a widely used internet marketing strategy. The basic idea of link wheels is to create a pattern of links which flow from one website to another which would finally link to a targeted website requiring promotion.

Yes link wheel helps little bit.

I also have doubt regarding link wheel.

According to my view linkwheel submission is not needed for the seo process .....

A link wheel is a linking strategy that uses a group of sites to make one site appear to be an authority site. You can use all the websites which allow you to add content and provide do follow back links and you are suppose to create links in circular way. Ideal link wheel should have content which can be partition in way which connects each other in circular sequence with meaningful way.

Link wheel is nothing but a wheel in SEO terms your website will be at the concentration point and all the articles and press and blogs linking to the website and all these blogs and article and press release are linked to each other , it will be very hard to get understood about this , i suggest you to do some research on it and make a conclusion .

Link Wheel is not effective now.
But you can try Link Trundle that is improved way of Link Wheel to get good rankings and traffic for your site.

I suggest you to submit fresh content every time for every submission. With this practice you will not face problem of duplicate content and you will have best revert of your submission.