## 1 Introduction  
The asymmetric war tactics used by terrorists lead them to prepare attacks of various kinds, and one of their main actions since the beginning of terrorism is the use of Improvised Explosive Devices (IEDs). Globally, since the end of 2001, there has been an increase in all forms of terrorism. Bombings constituted the majority of terrorist attacks in 2017, representing 47% of all attacks, these being the most common in countries affected by conflicts (around 50% of attacks), compared to 34% of attacks in countries that did not experience conflict [1]. An IED is defined by the United Nations as \"a device placed or fabricated in an improvised manner incorporating destructive, lethal, noxious, pyrotechnic, or incendiary chemicals and designed to destroy, incapacitate, harass, or distract. It may incorporate military stores but is normally devised from nonmilitary components\" [2]. The word \"improvised\" should not lead us to consider it as a system that is not very elaborate or is ineffective and lacking in technology [3]. Since the first Orsini bomb that contained gunpowder as an explosive charge and a percussion activation system (used in 1858 by the Italian [PERSON] in an assassination attempt on the French Emperor [PERSON]), IEDs have evolved technologically into the most recent UAV-IEDs used in Islamic terrorism [4]. Additionally noteworthy is the latent threat of attack with Chemical, Biological, Radiological, or Nuclear (CBRN) agents to be disseminated with an explosive, such as in a frustrated attack at Izmailovsky Park in Moscow in 1995, in which Chechen terrorists attached a source of Cesium 137 to an explosive device, known as a dirty bomb [5]. In spite of how advanced the electronic systems may be, and the various configurations that an IED can adopt, which are as varied as the terrorist's imagination, they all contain some basic elements, such as an activation system, an initiation system, an explosive charge, and a container (Figure 1). Once an IED, or a suspicious object, has been detected, only Explosive Ordnance Disposal (EOD) technicians can act to neutralize or deactivate it. The deactivation of an IED consists of causing physical-chemical changes in such a way that some of the systems necessary for the explosion to take place are interrupted. Undoubtedly, the final objective of the deactivation is to achieve the total disruption of the IED so that its components are separated, and the explosion cannot take place in any way, but intervention on the device carries the risk of accidentally causing an explosion or activating some \"trap system\" installed by the bombmaker. Therefore, one of the main security measures that can guarantee the protection of the technician is the distance from the IED at the time of action. There are several systems and procedures used to work remotely; one of them is the use of high-speed water projection devices using explosives: the water penetrates the IED, causing the disruption of the activation and/or initiation system, while not completely destroying the components of the device. The main advantage of water is its great power to dissipate heat and its humidification capacity, compared to metallic plasma that is projected by other sorts of devices, such as those used against Unexploded Ordnances (UXOs), i.e., shaped loads or Explosively Formed Projectiles (EFPs) [6]. Among these water projection counter-IED devices, whose use dates back to the 1980s [7], two different types are found according to the direction of the projected water: directional and omnidirectional devices. Directional devices project water in a predominant direction--some through the use of an explosive sheet placed in a certain position [8] or directed in the form of a high-speed jet, where the explosive that drives the fluid is centered and the water is projected radially (spray water).