Introduction of a Supercritical Kerosene Test Bench Based on One-Stage Electric Heater with Large Current
A kind of supercritical kerosene heat transfer test bench was introduced in this article. It uses large current to heat the stainless steel tube directly and then the kerosene flowing inside the tube can be heated. A kind of needle valve is used to adjust the kerosene mass flow rate and a kind of backpressure valve is used to adjust the pressure inside the test tube. Insulating materials are laid at the two sides of the tube to prevent electrical leakage. Heat flux is calculated by measurements of the voltage and current. Kerosene is rapidly heated to high temperatures while the wall temperature is below the safety limit by increasing the tube length and thickness. The electric heater could effectively simulate the heat flux of a scramjet engine chamber with a maximum power of about 28KW. Kerosene within 15g/s could be quickly heated to 1000K with this system.
Experiments on supersonic combustion of supercritical kerosene
Characteristics of supersonic combustion by injecting supercritical kerosene fuel into a Mach 2.5 crossflow at various preheat temperatures and pressures were investigated experimentally.A two-stage heating system has been designed and tested,which can prepare heated kerosene of 0.8 kg up to 950 K at pressure of 5.5 MPa with minimum/negligible fuel coking.Supersonic combustion tests under the similar stagnation conditions and kerosene equivalence ratios demonstrated that the combustion efficiency when using supercritical kerosene injection increased approximately 10%~20% over that using liquid kerosene injection,while it was comparable to that using effervescent atomization.
Laminar heat or mass transfer in rectangular channels and in cylindrical tubes for fully developed flow: comparison of solutions obtained for various boundary conditions
Abstract A comparison is made of results obtained with various boundary conditions at the wall of the channels. By comparing blood Sherwood numbers for finite wall resistance with those for constant concentration boundary condition only a small variation is found for various points along the blood channel.