Constand Volume reactor
Constant-volume combustion bombs play an extremely crucial role in the field of combustion research. On one hand, it can accurately explore the combustion characteristics of fuels. It not only precisely measures important parameters such as combustion speed, flame propagation speed and the auto-ignition delay time of fuels but also reveals the underlying mechanism of combustion reactions in detail through in-depth analysis of combustion products. On the other hand, it can effectively simulate the combustion environment inside an engine, thereby providing essential key data for the optimization of engine design and fuel research and development. It comprehensively evaluates the combustion performance of fuels under various operating conditions and helps promote technological innovation and development in related fields.
The Constant-volume reactor experimental platform of Northwestern Polytechnical University includes two sets of experimental systems, namely the vertical constant-volume reactor experimental system (V-CVR, as shown in Figure 1) and the horizontal constant-volume reactor experimental system (H-CVR, as shown in Figure 2). The V-CVR is mainly used for visualizing the droplet titration combustion and jet to jet combustion characteristics of self-igniting liquid propellants and oxidants; The H-CVR is mainly used for experimental research on laminar flame speed characteristics (LFS) of conventional liquid or gas fuels, as well as the ignition characteristics of self-igniting gas and liquid fuels under gaseous conditions in opposition to oxidants. In practical experiments, it is necessary to coordinate with high-speed cameras and shadow graph machines.
Fig. 1. Physical photo of vertical constant-volume reactor experimental system (V-CVR) in NPU
Fig. 2. Psysical photo of horizontal constant-volume reactor experimental system (H-CVR) in NPU
The following figure is a schematic diagram of the V-CVR experimental system used for testing the droplet titration combustion experiment of self-igniting liquid propellants and oxidants. The core of the system is a peristaltic pump that can control the size and flow rate of fuel droplets for fuel injection. Below the outlet of the peristaltic pump is a transparent container containing oxidants located inside the projectile. This experiment uses high-speed cameras for data acquisition and analysis.
Fig. 3. Scheme diagram of self-igniting liquid propellants and oxidants droplet titration combustion experimental system
Figure 4 shows a schematic diagram of the H-CVR experimental system used for measuring laminar flame velocity. This device can accurately measure the propagation speed of laminar flames in a constant volume environment, providing important data for combustion research.
Fig. 4. Scheme diagram of laminar flame speed experimental system
Figure 5 shows a schematic diagram of the H-CVR experimental system used for studying the ignition characteristics of self igniting gas fuels or self igniting liquid fuels under gaseous conditions in opposition to oxidants. The core of this device is to control the contact between oxidant and fuel gas at the center of the combustion chamber through solenoid valves and mass flow meters, and to collect and analyze data through high-speed cameras and schlieren systems.
Fig. 5. Scheme diagram of self igniting gas and liquid fuels ignition characteristics experimental system
Figure 6 shows a schematic diagram of the V-CVR experimental system used for the combustion characteristics of self igniting liquid fuel jets. The core of the device adds two high-pressure common rail pipelines and customized nozzles based on Figure 2, which can control the fuel and oxidizer to meet, and self-ignite in the center of the projectile in the form of injection. Data acquisition and analysis are carried out through high-speed cameras.
