Improved heat transfer is very important for the energy efficiency, higher performance, and size reduction of a system. In this context, the paper presents an efficient way for improving mixed convection heat transfer in a grooved channel by dividing total flow into main flow and injection under the assisting flow configuration. The influences of the pertinent injection parameters (e.g., position, size, and injection flow) are investigated systematically for Richardson number 0.1-10 and Reynolds number 50-200 using an in-house CFD code. The results reveal that performance with injection is always superior and heat transfer enhancement is found to increase from 50 to 218% depending upon injection, Richardson number, and Reynolds number. © 2015 Taylor and Francis Group, LLC.